We've had quite a few issues with OOS Sync cue lists being unsolo'd. We haven't yet managed to find a consistent reproducer but sometimes one list will be unsolo'd whilst another continues to have solo enabled which is a little bizarre.
If the main list is solo'd we have never seen this occur, only when one of the executed lists is solo'd itself.
We're back on 2.0.1 at the moment.
Cheers
Dan