Leopardmask

Update: this bug is still happening in 1.21.8rc1.

If this information helps, the stars in the sky are showing a similar glitch. I hadn’t mentioned it elsewhere in the report, because it seemed off-topic, but it’s the same visual flicker effect, so I imagine it might be related.

It is still happening in 1.21.7. I took still screenshots and gathered more information; the flickering seems worst in this area:

And doesn’t happen at all when I’m in some other locations, or looking directly at this specific wall sign (other wall signs in the area don’t affect the bug when looked at):

Here are the requested images with debug screen open. The one pointed at the sky is a moment of no flickering at all; the two looking into the distance were during times of worst flickering. All were within a couple minutes of opening the game.

As for the claim I’m running modded: I’m guessing this was assumed based on the extra HUD info, which is from a datapack. I do have a few minor datapacks running, but none that should affect visuals or loading at all, and all are fully up to date with the version. Otherwise, this is a completely vanilla instance.