Minecraft pe 1.14.1 keeps freezing on loading screen

Minecraft keeps crashing on my iPad Air 2. Sometimes i get to the home screen, others i get stuck on the page with the bars (loading screen after mojang logo) I dont know what happened. a similar issue appered on my iphone 7 plus where it would freeze during gameplay, but that was fixed my uninstalling and reinstalling a few times. i have tried to un and reinstall minecraft on this device, and i've tried cpoying my worlds back, but once i cpoied the worlds back, everything started hapening adain (i have 784 world btw )[i have two siblings]) i dont know whats hapening. can anyone please help me?