Looks like the April 2019 patch fixed the sim processor problem for me. Also the phone is staying on 4G and switching correctly.
Thanks for the patch and feedback.

I'm getting a SimProcessor error every time the devices switches from 4G to 3G. The error pops up as "SimProcessor" then triggers a screen lock and all internet sessions and calls gets terminated. This make the phone almost unusable because its switches in a period of seconds sometimes The...