problem getting unlocked mr1100 to connect att

Trying out a new internet reseller and wanting to use router #2 with that reseller.

Details: 

Reseller #1 :  Sent router #1 with ATT SIM card installed.  Works fine.

Reseller #2:  Allows BYOD, sent SIM card with their logo (not ATT)

Router #1 - MR1100 -  on start up shows the ATT logo, assume is an ATT version

Router #2 - MR1100 -  bought from Amazon, "unlocked" per the listing.  

After login to admin, every single setting and check box is set to exactly the same on both routers

Router #1 will connect to LTE with either SIM card

Router #2 will not connect with either SIM

Trying out a new internet reseller and wanting to use router #2 with that reseller.

Is there something else I can try or is this a bad router?

Thanks