Can't play multiplayer at all

Im on Minecraft PE and I cannot join any of my friends worlds at all. Only some can join mine although they have a lot of trouble. When they join they say they cannot break or build anything and the screen is very glitchy. All of my friends are either on Xbox or PC and they are just fine playing with each other. I've been trying to sort this for 3 hours. I've tried uninstalling minecraft, unadding then adding my friends, checked for updates, disconnected my WiFi, turned my phone on and off again but it's just stuck on the screen generating world locating server. I've left it on that screen for 5 mins and nothing happens. It's frustrating because now all of my friends are playing together and I can't join😞

thank you for reading and hopefully there can be a solution