10-14-2021, 12:28 PM
I was looking into this a while back because I had a similar issue. Here is what I found.
Wifi should be preferred since it has lower metric values in the routing table (or at least it should have). However I noticed that if IPv6 wasn't available on the wifi network, mobile data was used instead since IPv6 seems to be prioritized over IPv4. My workaround still is disabling IPv6 for the mobile data connection, so it doesn't matter if the wifi network supports IPv6.
Wifi should be preferred since it has lower metric values in the routing table (or at least it should have). However I noticed that if IPv6 wasn't available on the wifi network, mobile data was used instead since IPv6 seems to be prioritized over IPv4. My workaround still is disabling IPv6 for the mobile data connection, so it doesn't matter if the wifi network supports IPv6.