As for the match against Leverkusen, there is a clear chance that it's just that sometimes Bayern always has problems when playing against clubs that are under performing. But the possibility of this happening is very small for now.
Most chances Bayern Munich will be having to win here at BayArena Leverkusen because in last four meetings they never lost any game but this time we can expect good challenge from them as now they are also looking for better end of this season and good preparation for the next season.
This is exactly why I assumed they wouldn't be good in UCL like previous years as well, but they still are, and they managed to beat PSG somehow, a team that has having hard time in bundesliga beating PSG easily was a shocker to me as well.