“This device is using NextDNS with no configuration” error on a particular server

I've been greeting this error a lot lately: "This device is using NextDNS with no configuration."

Using the iOS app with profile configured. This happens a few times a day.

I initially thought it was some iOS bug. But it appears to only happen when never I'm connected through this particular Adelaide server only. When I got connected though another server, the issue disappears.

So I'm suspecting something's wrong with this server.

{
"status": "ok",
"protocol": "DOH",
"client": "",
"srcIP": "",
"destIP": "116.90.72.196",
"anycast": false,
"server": "gsl-adl-1",
"clientName": "nextdns-ios"
}