How to Resolve DNS Propagation Issues After Updating Records

I recently transferred the DNS for two domains from a registrar. I deleted one A record and converted another to a CNAME record. Unfortunately, the changes are not propagating globally, and A records still appear when I query against 1.1.1.1. I also cleared the cache via https://one.one.one.one/purge-cache/ and set the domain to developer mode.

Any ideas on how to fix this?