Buzzing after ~10 mins for IAA Plugins on iOS

A few of our users have reported that if they leave any of our apps running for around 10 minutes under IAA on iOS 13, the audio will stop and be replaced by a loud buzzing sound.

We’ve tested this with AUM and BIAS FX and confirmed that it affects not just our apps, but several other JUCE-based apps as well. It also affects the JUCE Inter-App Audio Effect Plugin demo when “Audio Background Capability” is enabled.

Disabling “Audio Background Capability” for our apps fixes the issue, but it also prevents MIDI input from working, so it’s not something we can do. Toggling this flag in Projucer seems to only affect a flag in standalone_plugin.plist.

We realize IAA is deprecated, but it’s something we still need to support because some of our users still rely on it.

Has anyone else run into this problem?

Bump. This happens on the latest tip with JUCE demo projects.