My best friend randomly cut me off, and i know they are alive

my best friend (online) just randomly stopped replying, i know they are alive cause of duelingo and other things like them posting on their accounts but they dont respond to my msgs, they even unfriended me on tiktok

i really dont know why, our last interaction was very normal but then nothing, its been a month

should i get the hint and what did i even do wrong,it was so our of the blue and im very heartbroken