"In case of DNS-based redirection, the client will send the hostname actually used to connect (this restores the pre-1.17 behaviour)"

I'm not sure if that's the problem but it's not fixed.
The problem that i reffer: If a server have blacklist he can purchase other domain and redirect to same server. For example minecraft-romania.ro have blacklist but they purchased mc-ro.ro and hawks-romania.ro and redirect to play.minecraft-romania.ro and that's how they bypass the blacklist.