Do not disturb recognizing wakeup?

Hi Guys,

since the last update I have a weird behaviour with my DND mode.

I have set it like: Sleeptime 23:00-18:00. So basically it may vibrate when I'm off from work and before I go to sleep.

Since the update it turns off somewhere in the morning hours and vibrates during work. 

I get a lot of notifications during the night but it won't vibrate there.

It it somehow detecting a wakeup and deactivating DND?

If so, how can I deactivate that ;)

Thank

Simon