There is a new issue for iOS 14 under following conditions:
- Your app is designed for iOS & distributed publicly
- Your app is sending audio (accessing the microphone)
- Your app will stop calls during its lifetime but continue running for a longer time
In this case iOS might continue showing the microphone indicator light. This is due to an earlier iOS 13 hotfix to workaround a bug with older Unity versions that could cause a crash or audio to stop working if the audio layer is being shut down. By now the latest Unity 2018 LTS & Unity 2019 LTS version do not have this issue anymore.
You can deactivate the workaround by editing the UnityCallFactory.cs and replace the line
All future versions of the asset will contain this as well.