When I started to play Minecraft 1.15.2, I immediately noticed that every block faraway from me had an outline, creating a grid-like pattern. I immediately brought down the Mipmap slider to off on instinct, and the problem went away, but with sacrificing visual quality.
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Thank you for your report!
We're actually already tracking this issue in MC-1794, so I resolved and linked this ticket as a duplicate.
If you would like to add a vote and any extra information to the main ticket it would be appreciated.
If you haven't already, you might like to make use of the search feature in the future to see if the issue has already been reported.
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