Possible EventEmitter memory leak detected

[qiweiii]

User says transactions are stuck on rpc:

(node:2474224) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 message listeners added to [Worker]. Use emitter.setMaxListeners() to increase limit
(node:2474224) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 message listeners added to [Worker]. Use emitter.setMaxListeners() to increase limit
(node:2474224) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 message listeners added to [Worker]. Use emitter.setMaxListeners() to increase limit

acala.yml

endpoint: wss://acala-rpc.aca-api.network
mock-signature-host: true
block: 4622429
db: ./acala.sqlite
resume: true
wasm-override: ./acala-2220.wasm
port: 7000

import-storage:
  Sudo:
    Key: 5GrwvaEF5zXb26Fz9rcQpDWS57CtERHpNehXCPcNoHGKutQY # Alice
  System:
    Account:
      -
        -
          - 5GrwvaEF5zXb26Fz9rcQpDWS57CtERHpNehXCPcNoHGKutQY
        - providers: 1
          data:
            free: 1000000000000000
  Tokens:
    Accounts:
      -
        -
          - 5GrwvaEF5zXb26Fz9rcQpDWS57CtERHpNehXCPcNoHGKutQY
          - token: AUSD
        - free: 1000000000000000
      -
        -
          - 5GrwvaEF5zXb26Fz9rcQpDWS57CtERHpNehXCPcNoHGKutQY
          - token: DOT
        - free: 1000000000000000

polkadot.yml

endpoint: wss://rpc.polkadot.io
mock-signature-host: true
# block: 17626686
port: 7002
db: ./polkadot.sqlite
# wasm-override: polkadot_runtime.compact.compressed.wasm

import-storage:
  System:
    Account:
      -
        -
          - 5GrwvaEF5zXb26Fz9rcQpDWS57CtERHpNehXCPcNoHGKutQY
        - providers: 1
          data:
            free: '10000000000000000000'
  Council:
    Members: [5GrwvaEF5zXb26Fz9rcQpDWS57CtERHpNehXCPcNoHGKutQY]
  PhragmenElection:
    Members:
      - who: 5GrwvaEF5zXb26Fz9rcQpDWS57CtERHpNehXCPcNoHGKutQY
        stake: 1000000000000
        deposit: 1000000000000
  TechnicalCommittee:
    Members: [5GrwvaEF5zXb26Fz9rcQpDWS57CtERHpNehXCPcNoHGKutQY]
  TechnicalMembership:
    Members: [5GrwvaEF5zXb26Fz9rcQpDWS57CtERHpNehXCPcNoHGKutQY]
  ParasDisputes:
    $removePrefix: ['disputes'] # those can makes block building super slow

[ermalkaleci]

nodejs/node#50136

[qiweiii]

Could be a node problem