Help, crackles when using External Effects

Hi guys,

After a while working, Cubase’s playback gradually start crackling up to a point of total trash.

I’ve got to go to the Studio Setup and ‘reset’ the audio board. The thing eventually fades back in after a couple of minutes.

Sometimes, the external effects simply stop sending signal outwards (clicking resetting also cures this)

My best guess is ‘External Effects’. I was working on this mix, using many external effects connections.

I am having difficulties to narrow down the bug. Yesterday I was working itb with video. No problems.

Any help, ideas, will be full-heartedly appreciated

ps1: I never had this sort o problem before. Started with 12
ps2: I found this post that may be the same issue Sync problem when using external effects:

Win 11 64bit 64GB RAM
Cubase 12.0.30