I noticed in the newest snapshot 19w41a that this bug no longer occurs. It can be marked as resolved.
Still occurs on 1.2.0.81.
I tested this again on the newest version I could get from the Windows 10 Store app (version 1.1.500.0 according to the store app) and the issue is still there.
I've updated all my drivers and deleted the com.mojang folder multiple times but it still doesn't work unfortunately.
Still a problem in 1.15-pre1.