NextDNS is connecting to Cloudflare...

I am using NextDNS on an Android phone (Google Pixel 7 Pro running GrapheneOS). Using Private DNS and when I run a DNS leak test on browserleaks.com I get two or more Cloudflare DNS servers, alongside the NextDNS ones. This is startling, to say the least; I deliberately avoid anything Cloudflare related. Read that multiple other users are facing the same issue, but could not find resolution, please point me in the right direction!