I noticed the same thing. Something changed on mobile web version of the app. It is now unusable for bullet chess. So, I downloaded the full iOS app. It’s better, but it doesn’t allow multiple premoves!?!? That’s a problem when trying to run a pawn down the board in an end game in bullet. I’m not sure what to do.
slow animation on phone app

I'm 700 elo trash, but still find the slow animations VERY ANNOYING, I am not able to play 1 min chess, cos 200-500 ms I am waiting for animation and can't do any moves/premoves during that time (the app just ignores me while the animation is in progress). I am using iOS app, we need setting for instant moves the same way it is available in settings in browser-chess
Thanks for listening