diff --git a/x-pack/platform/packages/shared/kbn-inference-endpoint-ui-common/src/components/configuration/configuration_field.test.tsx b/x-pack/platform/packages/shared/kbn-inference-endpoint-ui-common/src/components/configuration/configuration_field.test.tsx
new file mode 100644
index 0000000000000..646727fd9f9a0
--- /dev/null
+++ b/x-pack/platform/packages/shared/kbn-inference-endpoint-ui-common/src/components/configuration/configuration_field.test.tsx
@@ -0,0 +1,253 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0; you may not use this file except in compliance with the Elastic License
+ * 2.0.
+ */
+
+import React from 'react';
+import { render, screen, fireEvent } from '@testing-library/react';
+import { ConfigInputField, ConfigNumberField } from './configuration_field';
+import { FieldType } from '../../types/types';
+import type { ConfigEntryView } from '../../types/types';
+
+describe('ConfigInputField', () => {
+  const createConfigEntry = (overrides: Partial<ConfigEntryView> = {}): ConfigEntryView => ({
+    key: 'url',
+    isValid: true,
+    label: 'URL',
+    description: 'The URL endpoint',
+    validationErrors: [],
+    required: false,
+    sensitive: false,
+    value: null,
+    default_value: 'https://api.example.com/v1',
+    updatable: true,
+    type: FieldType.STRING,
+    supported_task_types: ['text_embedding'],
+    ...overrides,
+  });
+
+  const defaultProps = {
+    isLoading: false,
+    validateAndSetConfigValue: jest.fn(),
+  };
+
+  beforeEach(() => {
+    jest.clearAllMocks();
+  });
+
+  it('renders with default value when value is null', () => {
+    const configEntry = createConfigEntry({ value: null });
+    render(<ConfigInputField {...defaultProps} configEntry={configEntry} />);
+
+    const input = screen.getByTestId('url-input');
+    expect(input).toHaveValue('https://api.example.com/v1');
+  });
+
+  it('renders with actual value when value is provided', () => {
+    const configEntry = createConfigEntry({ value: 'https://custom.url.com' });
+    render(<ConfigInputField {...defaultProps} configEntry={configEntry} />);
+
+    const input = screen.getByTestId('url-input');
+    expect(input).toHaveValue('https://custom.url.com');
+  });
+
+  it('allows user to clear the field completely without resetting to default', () => {
+    const validateAndSetConfigValue = jest.fn();
+    const configEntry = createConfigEntry({
+      value: null,
+      default_value: 'https://api.example.com/v1',
+    });
+
+    render(
+      <ConfigInputField
+        {...defaultProps}
+        configEntry={configEntry}
+        validateAndSetConfigValue={validateAndSetConfigValue}
+      />
+    );
+
+    const input = screen.getByTestId('url-input');
+
+    // User clears the entire field
+    fireEvent.change(input, { target: { value: '' } });
+
+    // The input should be empty, not reset to default
+    expect(input).toHaveValue('');
+    expect(validateAndSetConfigValue).toHaveBeenCalledWith('');
+  });
+
+  it('does not reset to default after rerender when field is cleared', () => {
+    const validateAndSetConfigValue = jest.fn();
+    const configEntry = createConfigEntry({
+      value: null,
+      default_value: 'https://api.example.com/v1',
+    });
+
+    const { rerender } = render(
+      <ConfigInputField
+        {...defaultProps}
+        configEntry={configEntry}
+        validateAndSetConfigValue={validateAndSetConfigValue}
+      />
+    );
+
+    const input = screen.getByTestId('url-input');
+
+    // User clears the entire field
+    fireEvent.change(input, { target: { value: '' } });
+
+    // Simulate parent form updating value prop to null (as it converts '' to null)
+    rerender(
+      <ConfigInputField
+        {...defaultProps}
+        configEntry={{ ...configEntry, value: null }}
+        validateAndSetConfigValue={validateAndSetConfigValue}
+      />
+    );
+
+    // Should still be empty, not reset to default
+    expect(input).toHaveValue('');
+  });
+
+  it('allows user to type a new value after clearing', () => {
+    const validateAndSetConfigValue = jest.fn();
+    const configEntry = createConfigEntry({
+      value: null,
+      default_value: 'https://api.example.com/v1',
+    });
+
+    render(
+      <ConfigInputField
+        {...defaultProps}
+        configEntry={configEntry}
+        validateAndSetConfigValue={validateAndSetConfigValue}
+      />
+    );
+
+    const input = screen.getByTestId('url-input');
+
+    // User clears and types new value
+    fireEvent.change(input, { target: { value: '' } });
+    fireEvent.change(input, { target: { value: 'https://new.url.com' } });
+
+    expect(input).toHaveValue('https://new.url.com');
+    expect(validateAndSetConfigValue).toHaveBeenLastCalledWith('https://new.url.com');
+  });
+
+  it('is disabled when isLoading is true', () => {
+    const configEntry = createConfigEntry();
+    render(<ConfigInputField {...defaultProps} configEntry={configEntry} isLoading={true} />);
+
+    const input = screen.getByTestId('url-input');
+    expect(input).toBeDisabled();
+  });
+
+  it('is disabled in edit mode when field is not updatable', () => {
+    const configEntry = createConfigEntry({ updatable: false });
+    render(<ConfigInputField {...defaultProps} configEntry={configEntry} isEdit={true} />);
+
+    const input = screen.getByTestId('url-input');
+    expect(input).toBeDisabled();
+  });
+
+  it('shows invalid state when isValid is false', () => {
+    const configEntry = createConfigEntry({ isValid: false });
+    render(<ConfigInputField {...defaultProps} configEntry={configEntry} />);
+
+    const input = screen.getByTestId('url-input');
+    expect(input).toHaveAttribute('aria-invalid', 'true');
+  });
+});
+
+describe('ConfigNumberField', () => {
+  const createConfigEntry = (overrides: Partial<ConfigEntryView> = {}): ConfigEntryView => ({
+    key: 'max_tokens',
+    isValid: true,
+    label: 'Max Tokens',
+    description: 'Maximum number of tokens',
+    validationErrors: [],
+    required: false,
+    sensitive: false,
+    value: null,
+    default_value: 1024,
+    updatable: true,
+    type: FieldType.INTEGER,
+    supported_task_types: ['text_embedding'],
+    ...overrides,
+  });
+
+  const defaultProps = {
+    isLoading: false,
+    validateAndSetConfigValue: jest.fn(),
+  };
+
+  beforeEach(() => {
+    jest.clearAllMocks();
+  });
+
+  it('renders with default value when value is null', () => {
+    const configEntry = createConfigEntry({ value: null });
+    render(<ConfigNumberField {...defaultProps} configEntry={configEntry} />);
+
+    const input = screen.getByTestId('max_tokens-number');
+    expect(input).toHaveValue(1024);
+  });
+
+  it('renders with actual value when value is provided', () => {
+    const configEntry = createConfigEntry({ value: 2048 });
+    render(<ConfigNumberField {...defaultProps} configEntry={configEntry} />);
+
+    const input = screen.getByTestId('max_tokens-number');
+    expect(input).toHaveValue(2048);
+  });
+
+  it('allows user to change the value', () => {
+    const validateAndSetConfigValue = jest.fn();
+    const configEntry = createConfigEntry({
+      value: null,
+      default_value: 1024,
+    });
+
+    render(
+      <ConfigNumberField
+        {...defaultProps}
+        configEntry={configEntry}
+        validateAndSetConfigValue={validateAndSetConfigValue}
+      />
+    );
+
+    const input = screen.getByTestId('max_tokens-number');
+    fireEvent.change(input, { target: { value: '512' } });
+
+    expect(input).toHaveValue(512);
+    expect(validateAndSetConfigValue).toHaveBeenCalledWith('512');
+  });
+
+  it('is disabled when isLoading is true', () => {
+    const configEntry = createConfigEntry();
+    render(<ConfigNumberField {...defaultProps} configEntry={configEntry} isLoading={true} />);
+
+    const input = screen.getByTestId('max_tokens-number');
+    expect(input).toBeDisabled();
+  });
+
+  it('is disabled when isPreconfigured is true', () => {
+    const configEntry = createConfigEntry();
+    render(
+      <ConfigNumberField {...defaultProps} configEntry={configEntry} isPreconfigured={true} />
+    );
+
+    const input = screen.getByTestId('max_tokens-number');
+    expect(input).toBeDisabled();
+  });
+
+  it('is disabled in edit mode when field is not updatable', () => {
+    const configEntry = createConfigEntry({ updatable: false });
+    render(<ConfigNumberField {...defaultProps} configEntry={configEntry} isEdit={true} />);
+
+    const input = screen.getByTestId('max_tokens-number');
+    expect(input).toBeDisabled();
+  });
+});
diff --git a/x-pack/platform/packages/shared/kbn-inference-endpoint-ui-common/src/components/configuration/configuration_field.tsx b/x-pack/platform/packages/shared/kbn-inference-endpoint-ui-common/src/components/configuration/configuration_field.tsx
index da66c0b213a83..a2bc4febf2166 100644
--- a/x-pack/platform/packages/shared/kbn-inference-endpoint-ui-common/src/components/configuration/configuration_field.tsx
+++ b/x-pack/platform/packages/shared/kbn-inference-endpoint-ui-common/src/components/configuration/configuration_field.tsx
@@ -47,8 +47,12 @@ export const ConfigInputField: React.FC<ConfigInputFieldProps> = ({
   );
 
   useEffect(() => {
-    setInnerValue(!value || value.toString().length === 0 ? defaultValue : value);
-  }, [defaultValue, value]);
+    // Only sync from external value if it has actual content
+    // Don't reset to default when user clears the field (value becomes null)
+    if (value != null && String(value).length > 0) {
+      setInnerValue(value);
+    }
+  }, [value]);
   return (
     <EuiFieldText
       disabled={isLoading || (isEdit && !updatable)}
@@ -124,8 +128,12 @@ export const ConfigNumberField: React.FC<ConfigInputFieldProps> = ({
   const { isValid, value, default_value: defaultValue, key, updatable } = configEntry;
   const [innerValue, setInnerValue] = useState(value ?? defaultValue);
   useEffect(() => {
-    setInnerValue(!value || value.toString().length === 0 ? defaultValue : value);
-  }, [defaultValue, value]);
+    // Only sync from external value if it has actual content
+    // Don't reset to default when user clears the field (value becomes null)
+    if (value != null && String(value).length > 0) {
+      setInnerValue(value);
+    }
+  }, [value]);
   return (
     <EuiFieldNumber
       fullWidth