Hello, I would like to add something to the issue UE-86170.
When a performance drop happens, I get this warning:
LogAudioMixer: Warning: Audio device removed, falling back to other windows default device.
LogTemp: Resetting audio stream to device id
LogAudioMixer: Display: 0: FrontLeft
LogAudioMixer: Display: 1: FrontRight
I tried to unplug my speakers - the problem went away immediately. The speakers work fine, on the other hand. I watch videos, listen to music. I updated the drivers.
The speakers are Creative Gigaworks T20 Series II. Not sure if that is important.