I don’t know if it is a common issue, but I have a month old Support ticket on this issue that is still unsolved. In my case, it was narrowed down to time-based Routines that were failing to change Mode (all other actions in the Routine executed correctly). Presence-based Routine triggers (e.g., “when everyone leaves”) worked, and continue to work. For the time being I have moved my time-based Routines to a smartapp, Rule Machine.
If your problem is similar, please open a Support ticket and reference mine, #154180 (open a trouble ticket in any event). Maybe if enough people complain about this they will do something about it.