(<s>SOLVED</s>) DNS-over-HTTPS (DoH) not using the server it should?

Follow-up question re: How to enable DNS-over-HTTPS (DoH) :

I’ve configured OpenDNS on my system, but it’s not working. I can reach InternetBadGuys.com but I shouldn’t be able to.

At first, I thought I’d set the setting* to disabled. It seemed to remain enabled…but I hadn’t noticed this at the bottom of the screen:

Your changes will take effect the next time you relaunch Brave

*Secure DNS lookups

Enables DNS over HTTPS. When this feature is enabled, your browser may try to use a secure HTTPS connection to look up the addresses of websites and other web resources. – Mac, Windows, Chrome OS, Android


But then I saw… more useful documentation: https://support.opendns.com/hc/en-us/articles/360038086532-Using-DNS-over-HTTPS-DoH-with-OpenDNS and I re-enabled DoH and now I again don’t understand why OpenDNS on my system is not working.

If Brave works like Chrome, I think it should be working.

(My nameservers are set as follows:
That’s OpenDNS, with Google and CloudFlare as backups. No, not a standard configuration, but it’s been my config for years and I haven’t traced a problem to it yet.)

Wait, now it is working. Stale cache perhaps? Ah, I hadn’t re-enabled DoH. I’d enabled it for the first time. It’s not the default, and the browser relaunch isn’t 100% necessary, but a good idea; stale cache wouldn’t have confused me.

Wait, now it’s NOT working.