So close - Mikrotik wAP LTE working with AT&T SIM card

If anyone has any suggestions anything would be appreciated. Trying to get an AT&T Prepaid account working from its SIM card being installed to the LTE Mikrotik device as mentioned. It is so frustrating because it appears like our LTE interface is making a connection but we can’t ping another public address straight through the LTE interface. Something is just a little wrong and we have tried all kinds of variations and chased advice on Internet. Please let me know if you have any suggestions. – Kevin

We need more datails…

What routerboard are you using?
What version on ROS and firmware of your routerboard are you using?
What LTE card are you using?
In what country are you? (To see LTE bands, if are compatible).
What antenna are you using? (Brand and model).
Coaxial cables? (Brand and model).

Regards.