okay I think I was able to narrow it down to:
loading larger projects (like the factory project) + inputs active
than 1 out of 3 times roughly it crackles only in the right channel but stops when the DTii is not busy anymore (the loading icon upper left corner disappears)
of course this is a little bit weird and surely some folks will not have this when they are going strictly to do the „one song per project“ thing in their workflow and if I would hav not started again on the factory content I think I also would ghave never witnessed this behaviour.
still waiting on elektron supports answer until I do or dont do anything about it.
was still able to use it without any problems on a blank project and even recorded my first jam ^^