well i got no clue why it isn’t working. Try making a new simple animation script and playing it if that works on both studio and in game. It’s probably your script that’s breaking things.
I have this problem too (had) I have a solution , you need to make your own animation or if it’s your group game then publish it as group animation then it’ll work !
Make sure the animation priority is higher than Core.
If that doesn’t work,
Make your own animation script.
The latter is not that difficult and is a way better solution to this problem; the default ROBLOX scripts are really janky, complicated and spanning hundreds of lines of code as a one size fits all type of solution for most games (so that people with no experience can create their own and have functioning characters), but if you’re looking forward to creating an RPG, just make your own animation controller. Another reason for making your own animation controller is that you can change between states more easily than you can with the current default animate script, which has next to zero fluidness or responsiveness when swapping out animations.