Z-fighting occurs on the faces of some blocks (caused by third-party game overlay applications)
Note
This issue is caused by third-party game overlay apps. Please disable Discord overlay, Steam overlay, Riva Tuner, etc. for Minecraft: Java Edition.
If you need assistance with troubleshooting this issue, please contact Community Support for assistance.
The bug
Items like saplings, flowers, vines, cobwebs, dripleaf, sugar cane, rails and any non-full block with similar properties cause constant z-fighting, it doesn't matter if they where manually placed or world-generated
This issue also makes the water rendering glitchy, rendering differently depending on the viewing angle, and makes the inner part of a block visible in spectator mode
After restarting the game it stopped happening, but just leaving and entering the world again didn´t help