That's interesting that the Cloudflare DNS worked for you over 4G. I tried connecting WARP+ on my end over Three mobile data, but the DNS queries still do not work.
What I meant about the VPN is WARP+ itself rather than a third party. However, the issue is that WARP+ is currently not available for the desktop, so depends on an App being able to tether the WARP+ connection established on the mobile. With Android's built-in tethering, it bypasses WARP+.