Netgear Nighthawk M6 Pro Repeated Internet Failures

There is a more current firmware version from AT&T that may resolve some of your issues.  Try to do a software update and see if it comes down.  The problem you may experience is that AT&T is allocating downloads in small batches so not everyone is getting the update at the same time.  I've found that the device will say your software is up to date when it is in fact not.  Repeated attempts to obtain an update seems to eventually allow for the update to come down.  Unfortunately, Netgear cannot speed up the process since it's totally up to AT&T to deliver the goods.