There's not much more for me to say, I'll include a picture of the issue.

It didn't show up in the screenshot for some reason, maybe the image got compressed and it was removed.

There, I got it.

Interesting, which resolution are you using and which Minecraft version? Some of the rendering code changed in 1.21 so I might've missed something. I'll probably take a while to fix this because I don't have a lot of time at the moment.

I am unfortunately not able to reproduce this. Could you try to see if the issue is gone if you launch the game without any other mods? If that is the case please attach a list of your mods as well.

I also have this.

@Xrey274 does this happen if you have no other mods installed as well? If so what mods are you using?

Im also using this and I have this also when it is on full screen with the taskbar. But when it is in the max full screen, the one without the taskbar and app name, It disappears. When I make the window small it disappears again. Im using Feather Client and Sodium, Centered Crosshair and some more mods that I don't think may affect this.

Could you check if this issue persists with the newest version (1.1.0 for 1.21.3)? I am not sure what caused this in the first place, but the change in sprite offsets from the newest release could have potentually fixed this.