Connecting to any server with mobile data reports “you’re not connected to the internet”

When attempt to join a server, it declines with “you’re not connected to the internet right now. Reconnect to play on servers”.

I have internet connected, using Optus cellar data. Speed test of about 10Mb/s.

All servers in the lists show the ping is ok, but still won’t allow connection.

If I change to wifi, I can connect. I can also play from desktop hotspot img through the same connection. Just not using cellular.

Some other posts say to enable cellular data for minecraft in the app settings. I have done this, but still no luck.