Certificates untrusted, secure connection problems after new ATT router

AT&T installed a new BGW210 router in our home two days ago, as part of an upgrade to the internet 1000 service. Ever since, all devices in our house (Mac, iPads, iPhones, Chromebooks) seem to have SSL problems. We get 'can't establish a secure connection' errors for some webpages. We get 'untrusted certificate' errors in iTunes, Zoom, and other applications/connections.

The problem comes and goes but it happens on all devices multiple times per day. It never happened before the router swap, therefore something is off with the router.

Are there security, DNS, SSL, or some other configurations on the router I can change to fix this?