870 with DNS issue

I'm having issues with DNS on my RBE870 with 1 satellite. I have fiber to the house from Visionary Broadband. All my cables are cat 6A shielded (including ethernet to the satellite). The 870 is connected directly to the modem (fiber to IP device). Router is set to use the modem DNS servers (google). Everything will be fine for a couple of hours after a router reboot and then suddenly you can't surf. When this happens I can ping any actual IPs but not any site like the url for google or yahoo. This happens on phones, Macs, Windows and tablets. If I add DNS servers to the computers/phones/tablets everything is fine. I have tried adding DNS severs to the router with no change (Cloudflare/Quad9/Open DNS/Google). Router & Satellite both have the most current firmware (V10.5.20.4_1.3.5). Anyone have any ideas?

Thanks

Jay