BG77 vs BG77LA and AT&T networks

We’re having connection issues in the US trying to get a network registration with a BG77LA-64-SGNS module.
Our SIM provider ask if this module is approved with AT&T, and showed me a iist with the AT&T approved modules, which list “BG77”.
But, we’re using a BG77LA.
Does that makes any difference?
I can’t find ANY documentation anywhere that describes the variants.

BG77LA is BG77 so it is also approved with AT&T.

We are an IoT SIM card provider and we have a customer using this BG77LA-64-SGNS module. Are you saying that there are no variants for the BG77 when it comes to supported cellular bands? I see “LA” and I think Latin America. Is this a global module with bands B1/B2/B3/B4/B5/B8/B12/B13/B18/B19/B20/B25/B26/B27/B28/B66/B85 for Cat M1 and B1/B2/B3/B4/B5/B8/B12/B13/B18/B19/B20/B25/B28/B66/B71/B85 for Cat NB2 available?

Thanks!