Minecraft pocket edition multiplayer problems?

I have mcpe (minecraft pocket edition) on my apple mobile phone. 2 of my friends wanted to join my world, we're all friends through x-box, but it still doesn't work. I can enter the world of my friends but if you want mine it always says, Wow, the server is really popular, come back later, maybe there will be a free space '

i don't know why it doesn't work my internet is actually average good i have restarted my game several times but it still doesn't work

This is a bug. What you get displayed ('Wow the server is really popular, come back later, maybe there will be a burst free') means that the server / world is full and nobody can join. The multiplayer is very buggy at Bedrock and often doesn't work. Better get a paid realm, that works in 99% of the cases