4g and wifi both on

[fragologist]

If I keep my mobile data and wifi on will the phone favor one over the other?

 

[SpookDroid]

Yes, WiFi (unless it detects connection or connectivity issues) will always be preferred. Bear in mind that, unless WiFi calling is active, MMS messages will require using mobile data and you might see those two connections active at the same time when receiving/sending such messages.

 

[bandofbrothers2112]

If you long press on your Wi-Fi icon there are options where you can set preferences under advanced.. Apologies of you've seen that.