Try alternate way of checking for device failures.

src/audio/IAudioDevice.h

@@ -43,6 +43,8 @@ class IAudioDevice
     virtual void start() = 0;
     virtual void stop() = 0;
 
+    virtual bool isRunning() = 0;
+
     // Sets user friendly description of device. Not used by all engines.
     void setDescription(std::string desc);
 

src/audio/PortAudioDevice.cpp

@@ -57,6 +57,11 @@ PortAudioDevice::~PortAudioDevice()
     }
 }
 
+bool PortAudioDevice::isRunning()
+{
+    return deviceStream_ != nullptr;
+}
+
 void PortAudioDevice::start()
 {
     PaStreamParameters streamParameters;

src/audio/PortAudioDevice.h

@@ -32,11 +32,13 @@ class PortAudioDevice : public IAudioDevice
 public:
     virtual ~PortAudioDevice();
 
-    virtual int getNumChannels() { return numChannels_; }
-    virtual int getSampleRate() const { return sampleRate_; }
+    virtual int getNumChannels() override { return numChannels_; }
+    virtual int getSampleRate() const override { return sampleRate_; }
 
-    virtual void start();
-    virtual void stop();
+    virtual void start() override;
+    virtual void stop() override;
+
+    virtual bool isRunning() override;
 
 protected:
     // PortAudioDevice cannot be created directly, only via PortAudioEngine.

src/audio/PulseAudioDevice.cpp

@@ -55,6 +55,11 @@ PulseAudioDevice::~PulseAudioDevice()
     }
 }
 
+bool PulseAudioDevice::isRunning()
+{
+    return stream_ != nullptr;
+}
+
 void PulseAudioDevice::start()
 {
     pa_sample_spec sample_specification;

src/audio/PulseAudioDevice.h

@@ -36,11 +36,13 @@ class PulseAudioDevice : public IAudioDevice
 public:
     virtual ~PulseAudioDevice();
 
-    virtual int getNumChannels() { return numChannels_; }
-    virtual int getSampleRate() const { return sampleRate_; }
+    virtual int getNumChannels() override { return numChannels_; }
+    virtual int getSampleRate() const override { return sampleRate_; }
 
-    virtual void start();
-    virtual void stop();
+    virtual void start() override;
+    virtual void stop() override;
+
+    virtual bool isRunning() override;
 
 protected:
     // PulseAudioDevice cannot be created directly, only via PulseAudioEngine.

src/main.cpp

@@ -2679,10 +2679,6 @@ void MainFrame::startRxStream()
         {
             CallAfter([&, error]() {
                 wxMessageBox(wxString::Format("Error encountered while processing audio: %s", error), wxT("Error"), wxOK);
-
-                // Force shutdown of connection
-                wxCommandEvent tmpEvent;
-                OnTogBtnOnOff(tmpEvent);
             });
         };
 
@@ -2912,6 +2908,16 @@ void MainFrame::startRxStream()
         }
 
         if (g_verbose) fprintf(stderr, "starting tx/rx processing thread\n");
+
+        // Work around an issue where the buttons stay disabled even if there
+        // is an error opening one or more audio device(s).
+        bool txDevicesRunning = 
+            (!txInSoundDevice || txInSoundDevice->isRunning()) &&
+            (!txOutSoundDevice || txOutSoundDevice->isRunning());
+        bool rxDevicesRunning = 
+            (rxInSoundDevice && rxInSoundDevice->isRunning()) &&
+            (rxOutSoundDevice && rxOutSoundDevice->isRunning());
+        m_RxRunning = txDevicesRunning && rxDevicesRunning;
     }
 }