Whenever i mistype something and try to fix it, the next letter gets removed.. for instance if i mistype " dance " as " adnce " and delete the A, then try to put it behind the D, it removes/replaces the N, if i type down the N it deletes C etc etc... it only started recently for me after christmas event begun and it's getting annoying kinda, it happened to me before too and only in the game during certain events

You pressed the INS key from your keyboard, press it again to disable it.