Severe VM performance degradation after sleep, FaceTime call, or audio output change (macOS 15.5 beta 2, M2 MacBook Air, UTM 4.6.4)

When running a Windows 11 virtual machine in UTM (version 4.6.4) for over an hour, the system gradually becomes less responsive. The issue becomes significantly worse in the following scenarios:
- After the MacBook is put to sleep and then woken up.
- After answering and ending a FaceTime or cellular call on the Mac.
- After changing audio output — for example, switching from AirPods Pro 2 back to the Mac's internal speakers.
In these cases, the VM becomes extremely sluggish. The first sign is choppy, stuttering audio. Then keyboard input becomes severely delayed, with a lag of around 4–5 seconds per key press. Restarting the VM or the UTM app is the only way to temporarily restore responsiveness.

## Steps To Reproduce:
1. Launch a Windows 11 VM in UTM (version 4.6.4) on a MacBook Air M2 with 8 GB RAM.
2. Use the VM for over an hour.
3. Trigger one of the following events:
- Put the Mac to sleep and wake it up.
- Receive and end a FaceTime or cellular call.
- Connect and disconnect AirPods Pro 2, switching audio back to internal speakers.
4. Observe performance degradation and audio stuttering.
## Expected behavior:

The virtual machine should remain fully responsive regardless of the host’s sleep state, audio routing, or call activity.
Host Machine:
- Device: MacBook Air with M2 chip
- RAM: 8 GB
- macOS version: Sequoia 15.5 beta 2
• UTM version: 4.6.4
Guest OS: Windows 11

## Additional context:

This issue makes longer VM sessions unreliable. A restart of the VM helps temporarily, but the degradation returns after one of the listed events. I’d appreciate any fixes or workarounds — thank you for your work on this awesome project!