Secure DNS is NOT being used AND device is connected to NextDNS.

Anyone get this?

All I have done is change the IPv4 and IPv6 DNS settings on my router to the exact ones that are shown on NextDNS and then on my phone inside the app iv clicked link ip, but it says SecureDNS is not being used? This is on my home router. Will this cause a big issue, or what exactly does it mean? I've looked on Google and can't find an answer.