Ethernet adapter being paused by router

I just started with Xfinity 2 days ago and have been having problems connecting to the internet using either of two computers that are connected to the router via Ethernet. In particular, my MacBook Pro is connected via an Asix Ethernet adapter. The adapter is reported as "offline" by the Xfinity app. Firefox has a banner at the top of most pages that says "You must log into this network to access the internet." and presents a login button. Clicking the button brings up a notification from Xfinity saying "This device is paused." However, I did not pause it and have no idea why this happened.

The problem seems to be fixable by power cycling the router; however, since I don't know the cause, I have no idea how to prevent it from happening again.

Thanks in advance.