Configuration Issue with iOS

I am stuck for many days to find a resolution getting NextDNS functioning on all iOS devices. I had Cloudflare Warp agent installed on all home devices, and I decided to move to NextDNS. I followed all the instructions to configure the DNS on iOS using the profile configuration, however nothing seems to work. All devices shows "Unconfigured".

I have updated all iOS devices to the latest update 15.5 but with no luck. I came across a few articles talking about VPN apps that may cause similar issued and followed the resolution steps but again with no luck.