[Bug]: CoreAudio device glitchy breakup in 8.0.9+ with differing input and output devices selected

[kevin--]

Detailed steps on how to reproduce the bug

1. regular app with AudioDeviceConfig based callback on macOS

2. set the Input and the Output device to be different devices

3. playback or record for a while

4. audio starts breaking up / buzzing / repeating buffers style of sounds

5. eventually goes totally silent

6. this line is getting hit continually when in this state

   • https://github.com/juce-framework/JUCE/blob/8.0.11/modules/juce_audio_devices/native/juce_CoreAudio_mac.cpp#L2088-L2089

Reverting to JUCE 8.0.6 (our previously used version which is before the CoreAudio changes) resolves the issue.

Unfortunately we want to update to 8.0.9+ to resolve #1595

What is the expected behaviour?

discontinuity only happens if the CPU is overloaded and audio stays clean

Operating systems

macOS

What versions of the operating systems?

macOS Sequioa 15.5

Architectures

Arm64/aarch64

Stacktrace

https://github.com/juce-framework/JUCE/blob/8.0.11/modules/juce_audio_devices/native/juce_CoreAudio_mac.cpp#L2088-L2089

Plug-in formats (if applicable)

No response

Plug-in host applications (DAWs) (if applicable)

JUCE-based host, using AudioDeviceManager + audio callback

Testing on the develop branch

The bug is present on the develop branch

Code of Conduct

• [x] I agree to follow the Code of Conduct

[szarvas]

I've been unable to reproduce this so far.

How long does it take for the first dropouts to appear?

Can you reproduce the issue with the AudioPluginExample_Standalone by adding some minimal modifications e.g. playing a sine wave in processBlock?

Do you have to select a particular sample rate and buffer size, and particular devices, or can you reproduce this with multiple different settings and different devices?