is possible that it cannot be reproduced. i found out that fast graphical processors don't have this problem.
this appeared to me too, found it today, before reading this message. i wanted to make a yt vid...
This happens to some other versions too...
This is the good ol' brightness bug
lol
IT IS BACK!!!!!! confirmd in 17w15a!
found this when building an underwater base.
MOJANG MICROSOFT ALARM!
please report it in the Jira for the Minecraft Bedrock codebase
https://bugs.mojang.com/projects/MCPE