Default (Primary) SIM keeps changing.

[VoiceOverDude]

I have dual esim enabled and data switching off. T-mobile is set to primary and my secondary esim is a voice only plan on a Verizon MVNO.

The phone keeps switching to the Verizon esim and that causes me to keep losing mobile data ability until I manually set T-Mobile to primary again. 

Sometimes my preferred primary sim lasts a few days, other times it changes the primary is almost immediatly.

Sometimes I've had to keep changing the primary back to T-Mobile several times a day.