The same issue as reported here on XDA. For me, this is with Screen On animations disabled and Screen Off animations enabled. I've not tested other configuratins.
This problem could possibly be resolved by keeping a black overlay on the screen after the screen turns off. This will make sure that when the screen on animation plays, that the screen is completely black.
This module no longer works on the latest xposed version because it includes the classes for xposed in it.
As per rovo89's changes on xposed here and here.