App incredibly slow and unstable

Hello everyone!

I have been an active player of MCPE (Now Bedrock edition) since about 2013, but I have had an issue plaguing me for the past year or so. Im on an iPhone 8 on 13.7 because I occasionally Jailbreak. however, for some reason, even when not jailbroken, whenever I open the app, it's unbearably slow, so slow that I can't even use it. I've tried to delete the app, tried googling answers, and doing a multitude of things but nothing will work. I'll attach a video for proof, but some assistance with the situation would be great!