dual pc streaming problem with sound

Hi ... I'm streaming and using two computers (dual pc).
I have a "Sound Blaster Zx" sound card in each of these PCs and these cards are connected via an optical cable.

The problem is that on a streaming PC I listen to the sound from the gaming PC and when I listen to this sound I hear a crack

The sound is otherwise great on a gaming PC and the same goes for Streaming PC! but how they have to work together is something wrong.

resp: it occurs to me that Digital-out sent sound and digital-in somehow receives it badly because when listening on a separate gaming PC, the sound is great and on a streaming PC as well. I was wondering if there is a difference in the quality of the optical cable or there may be a problem with some synchronization between the two cards?

I have Windows 11 Pro
v. 21H2
build 22,000,348

Unfortunately, I'm not sure now that it did the same thing on Windows 10, because I've had Windows 11 for a while now and viewers have noticed it until now.

Has anyone solved a similar problem?