Happens in a multiplayer world, havent seen if this happens in singleplayer too but after I alt + tab the horizon becomes glitchy or whatever that is. Also happens when I interact with certain blocks like when i sleep in a bed or open a chest. The reload does fix it but as soon as I do one of the actions listed above it glitches again. Tried deleting the config file, updating Iris, fabricAPI, sodium to the latest versions compatible with 1.21.10 yet it hasnt been fixed. Note: This ONLY happens with shaders, I dont know if its photon specifically though.