Alternatively you could use os-caddy as your DynDNS client with Cloudflare.https://docs.opnsense.org/manual/how-tos/caddy.html#dynamic-dns-in-client-mode
I do not recall anything in the release notes stating that there were changes to this functionality. The complete configuration was identical to earlier versions (meaning I didn't modify anything), and it worked without issue. In fact, I brought up the prior version and verified that it worked correctly. So, something changed somewhere in the latest version of OPNsense. If Cloudflare is selected as the service, it seems to me that it should completely ignore the username field if it is indeed superfluous. (Or better still, do not display the field if it's not appropriate to the service selected.)Thank you all for your suggestions.