Multiple VFOs w/ audio sinks causes hang on MacOS intel

[thirstyice]

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FIRST: Before reporting any bug, make sure that the bug you are reporting has not been reported before. Also, try to use the nightly version if possible in case I've already fixed the bug.

Hardware

• CPU: 2.6GHz 6-core Intel Core i7
• RAM: 32GB
• GPU: Radeon Pro Vega 16 (4GB)
• SDR: Local RTL-SDR

Software

• Operating System: MacOS Sequoia 15.7.1
• SDR++: 1.2.1 Oct 9 2025 (latest at time of writing)
• First discovered on build from Feb 13 2025

Bug Description
A clear description of the bug.
Using multiple VFOs w/ audio sink causes app to hang.

On the build from Feb 13 2025, selecting the audio sink on multiple VFOs would immediately cause the app to freeze + the spinning beach ball to appear.

On the latest build, selecting the audio sink on multiple VFOs causes radio reception to freeze (including the waterfall and FFT displays), but the interface will still function. At that point, attempting to change the sink back will cause the whole app to freeze + the spinning beach ball to appear, as before.

Steps To Reproduce

1. Open app + begin receiving
2. Add 2nd VFO
3. Set sink for 2nd VFO to Audio (Radio reception freezes)
4. Set sink back to None (whole app freezes)

Additional info
Might only happen when the sink is changed while receiving? While I was testing, the app froze as usual, but upon re-opening both sinks were set to audio, and it seems to work as expected.

But now disabling either VFO causes reception to freeze.
However if I disable both VFOs, reception un-freezes.
In summary, if both VFOs are in the same state (enabled or disabled), then it works as expected. If their states differ, then reception freezes.

Also, setting either sink to None while receiving still freezes the whole app.

[Nikotine1]

I have the same symptoms on MacOS. Running v1.2.1 build June 24, 2025.