konnichiwa

@Marilyn it only happens for me when I log out but maybe that's also because no one is at my region?

Someone had this issue around his nether portal destroyed it and the issue around the nether portal was fixed.

I have the same issues,  I am on a server and when I logged in my ware house/farm/etc became partially dark. Replacing torches helped but then it later when I logging in I got the same issue again.  Playing on hard + replacing all torches everytime is certainly not an option. Also it is expanding to other players on the servers who have the same issues.