Whenever I play a sound in FL Studio with my external synths, I have heavy crackles every few seconds. They only appear at 32 samples and less at 64 samples, at 128 samples it is 99.9% crackle-free if not 100%. Initially I thought my CPU was doing weird stuff like Hyperthreading or switching power modes. On my other machine with a much older Ryzen 5 I can do 32 samples on a Raydat HDSPe with absolutely no issues.

Then I noticed today that the crackles, though random, are very reliably coming when I click on things like the menu or switch the tabs in the settings page. Can this have to do with a conflict with the GPU?

I also noticed that everything works quite fine after a new boot when I start FL studio quickly, then after a minute the crackling starts.

I've tried switching off fast boot in Windows 11, Hyperthreading, Virtualization and the other bios options, startup items, remove services, fresh install...

Could another GPU help? Older drivers? Can I somehow assign different interrupts to the devices?

Thanks for any hint...