I am playing around with blocking DNS servers, after my Raspberry PiHole died. I am trying both NextDNS and ControlD and have set them up in Services/DNS Proxy/DOH and everything is working, and I can switch between them without issue.

I noticed that my Roku TV was still making calls to Google's servers at 8.8.8.8 and 8.8.4.4, so I set up two static routes, in order to push the requests back to the router/DOH. With the static routes, everything works. But if the static routes are enabled, and I switch from one DoH to the other, I lose the network, which then takes about 20 minutes to sort itself out. Now if I disable the routes and then switch the DOH servers, and then re-enable the routes, everything works right away.

I read about blocking Google's DNS servers, and it is pretty straightforward. There are many guides for multiply brands of routers. I did notice some of the guides suggest setting the metric to "2", but I have no idea if that would make a difference. TP-Link says the metric is a priority setting, yet some routers say it the number of hops, so I left it at "0", default as suggested by the "?" link in the ER605.

Any idea why it would do this?

Thanks!