DNS constantly drops out

Im using the custom DNS option in my router, pfSense in this case, entering the DNS primary and secondary addesses and hostnames to farward all DNS requests through Cloudflare from the router,

However, DNS just keeps dropping out. It can drop for up to 5 minutes. Removing those custom DNS server and say using google 8.8.8.8 resolves this issue.

Any reason you could think that this could be hapenning?

Thanks

I presume you mean that you are using 1.1.1.1 and 1.0.0.1, and are not using DOH or DOT?

Given the behaviour you are seeing it could be that one of those two addresses is being used incorrectly somewhere in your network (including in your ISP)

Visit the diagnostic page below, and share the link you get with your results.

Im using the dns servers and names provided here.

It would be DoT