set the routers DNS up. OpenWrt uses defaults for dnsmasq and assumes things at times. I ran into issues when i did similar to your config replacing dnsmasq with AdGuardHome.
As i dont require the router to be filtered. i explicitly set the router to have its own upstream that uses regular UDP dns which also avoids the NTP issue. (router doesnt have correct time and cannot update via secure DNS as the time is wrong)