Big Pink and Black Square Bug on my screen in my realm!

Hey Mojang. This is my first time creating a bug issue. My Minecraft just updated today since the armadillos and wolf variants arrived but thats not the issue. I just logged in to my realm to play survival as usual and i noticed a big pink and black square or bug that is in the top middle of my screen and i thought to myself maybe its because the mod/texture packs i have on my realm and its a new version of the game so I removed them but it was still there so I added them back. Is there a reason why it's on my screen? I also haven't restarted the app so I'll do that now but I just need an explanation on how to fix it. Thanks, Benny3K.