Multiplayer with friends (with cellular data) not working

I'm trying to play with a friend over cellular data whenever I'm not around wifi. We are both signed into our Microsoft accounts, set our settings to cellular data enable in the settings.

Before starting the world, my world settings is set to multiplayer so it's on, but when use cellular and I go into my world and go to multiplayer settings it is turned off and grayed out so I can't change it. 

I pause the game and have no invite option under my name when I use cellular. When I'm using wifi I have the option to invite people. My iOS settings are enabled that I can use cellular and so are theirs.

They always play on cellular data and it ONLY lets them join my world when I'm connected to wifi. Never with cellular..I makes no sense sense there's a setting to USE cellular data instead of wifi😞

Last week I was able to play with my cellular data and invite them with no issues. I was able to see the invite button under my name when I was not using wifi.

Im on iOS and so are they with the latest software update and with the latest game update..

I don't know why it's not working anymore😞 is there anyone that can help us out? Much appreciated.