There is in brain (not-so-)fun effect: consciousnesses are created by activity of physical neurons. If these consciousnesses are not used in the form of actually connecting to main consciousness and then are not used at all then brain can run signals right through groups of neurons which would make these consciousness not work correctly.
If that kind of activity happens then trying to force experiencing given consciousness will cause sharp unpleasant experiences I call "errors", it is type of dukkha. Like rather sharp and unpleasant experiences of something in this consciousness not working correctly.
Now these errors can be very strong or even very subtle. In the past I just called whole thing as "'routing issues".
These errors often happen during DN for the same reason as anything in DN: trying to use A&P minds. Like if we even drop to normal mind then any activity not compatible with that (A&P can in extreme case use completely different pathways not compatible with normal mind so there is collision, some times one way, some times two way) will cause experience of errors. DN also has other types of dukkha but this one is pretty common too.
Normally is totally not obvious what causes such routing issues because that requires knowing exactly where activity happens at any given moment to know that when routing issue happened it could be due to concrete limited number of other consciousnesses the better internal perception the better accuracy Having such insight allows just tuning them down until errors do not appear. Then focusing on resolving these collisions by perhaps routing signals differently.
Concluding if there is experience of errors it might be there is nothing wrong as much as it maybe was not used much in long time and mind got used to use some other consciousness and to optimize it ran signals though physical substrate of this consciousness which we now want to use. To use it the other one can e.g.. go to sleep temporarily. If one would like to have both active at the same time its just matter of working thought routing issues. How to resolve routing issues is different topic but usually some wiggling around and understanding what the issue is and issue will resolve itself.
Routing issues can prevent using consciousnesses entirely. The longer consciousness was not used or really not used at all the more signals can go through it and activating it might seem completely impossible or part of mind can feel like no go zone. How that feels depend on spread of errors. Lots of smaller connections going through substrate of consciousness will feel different than spread out bigger groupings of connections (which is the case which really feel like having error connections). Of course in mind everything is consciousness so any place which feels like is inaccessible can be said is due to routing issues and these issues are resolved in similar way.
I mention all this because it might be useful to someone. Always nicer to not have situations neurons assembling nice consciousness and then getting bombarded from sides with activity which makes no sense and is stressing them and with it rest of mind.
