MR5200 no data connection

Less than 90 day old mr5200 purchased directly from netgear

Today, absolutely no network data connection from either my unlimited data T-Mobile and att sim cards.

Both cards work in my new and unlocked mr6500 (firstnet registered).

Both sims work in various tablets as well.

Any ideas?

Went through support and they’re supposed to replace, but after charging 3 cards the 29.90 next day exchange fee - the netgear system continually gave an error.