When I read a forum problem I don’t quite understand I like to have a go as it usually uncovers an understanding of how to do something I hadn’t considered or it takes me off in new directions getting into it. This has an element of that, but whilst it seems clear (and detailed) to you and may be obvious to others I can’t see the obvious problem.
But it seems you have some sessions where it isn’t manifesting as a soft/hardware issue. That in itself makes it hard to test accurately as it would need to b the simplest repeatable configuration to replicate the problem. One thing that isn’t obvious to me is how you are using the cue though, are you using it as a bus to sample from or as outs.
I’ll certainly give the elements of the routing I understand a go to see if it gives some inspiration as to the cause. In the meantime hopefully an octatrack guru will spot what’s up.
Is there any chance the issue is mic fbk related, if it’s a ‘software’ issue it shouldn’t matter how the signals are getting in unless peaky inputs are triggering some metering issue.
Plus it may be a hardware issue, that’s why you need to table a repeatable route to recreating it or hope that it maks sense to someone reading it