In the rule logs, you can enable the Debug level in the filters.
I recently received one other report about state stays conditions with SmartThings. In that case, when we checked the details of the rule log showing the state stays failed, we saw that the timestamp of the state was 2 seconds later than the reported event timestamp which is why the system was thinking that another event must have occurred (per the timestamp from the state being later than the original triggering event) and thus the state stays condition wasn’t passed.