DoH stops working after upgrading to v7.12 because after the upgrade, the clock gets reset to 1970 which means the SSL certificate fails because the date is wrong. The clock doesn't update because DNS isn't working which also blocks update to 7.14. Workaround is to manually set the date and time once and it all starts working again. I was prompted to check the logs when the v7.14 update failed to download.

So a question - should DNS failover to the dynamic servers if DoH is offline? I guess I could uncheck Verify DoH Certficate but that's not ideal.

PS. It's DNS, it's always DNS