BYOP - LG G5 from Verizon

Morning!
I have my old Verizon LG G5 that had a broken screen.  Replaced the screen and want to use it with my Cricket Plan.
Well, swapped in the SIM Card and it selected Global network, which is 3G or less and one bar.
Went through the settings suggested under the BYOP setup, and had LTE last for a short period last night. Somewhere over the night it switched back to Global.
With the Samsung Cricket phone, we go from 2 to 3 bars, not always LTE where we live.

Question 1: How do I get it to stay on the correct network? 
Question 2: Is there a way to get rid of the Verizon programming in the phone?

Thank You!