Not possible to send or receive MMS

For me, it’s not possible to receive or send MMS with the phone using correct info in the MMS settings in SMS preferences, only works if I switch the APN in mobile settings. This makes it so that I can only use either mobile data for internet, or for receiving and sending MMS, not both at the same time.

I live in Sweden, and are using Fello (which is a part of telia)

This may be a known limitation. I suggest a forum search.

It indeed appears to be, and a long standing one at that.