cant change username

okaaayy so basically, my profile edit access got suspended last night for 24 hrs. i was able to appeal this suspension after the first two hours though. i can fully edit my profile, but for some reason i can't change back to my old username? it says "Couldn't update username. Try another." i haven't changed it in the last 30 days, nor is my username taken so i find this very strange ?? please lmk if there's anything i can do 🥹 i really don't wanna choose a new username since i have my watermark on everything already 💔