I have this same issue..
When attempting to connect to friends or realms while connected to LTE data an error stating that "You must be connected to WIFI to play with your friends." This only happens on LTE. I have set the connection to be "not metered" and it still does not work.
Steps:
Disconnect from wifi and/or ethernet.
Connect to LTE/cellular service.
Launch Minecraft Windows 10 edition.
Attempt to connect to friends or Realm.
Observed Results:
Pop up dialog stating "You must be connected to WIFI to play with friends"
Fails to connect.
Expected Results:
Connect to server and friends as is typical when using Cellular on a mobile device.
Screen Captures:
[media]Windows 10: No option to enable cellular data.
[media]Android: Option enabling cellular data.
[media]LTE not set to metered.
[media]Notes:
As noted in the original post there is no option within the Windows 10 version of Minecraft to allow for play over cellular data like there is on the mobile counterparts. This would be very handy to allow those with an LTE enabled laptop/tablet to play while on the go.
Skajjie, This pack worked!! Thank you. I didn't realize at first that I needed to activate it, but now it's working perfectly.
Thank you very much for following through on this.