Can't get wildcard domains to work with Cloudflare and Docker

I'm trying to follow this guide:

and getting the following errors:

I can't figure out for the life of me why it's not working and I can't make out any helpful messages to know what to try next.

On Cloudflare I have an A record pointing to my IP address, and a CNAME record pointing to my domain.
Is this possibly a Cloudflare issue? I had this working yesterday and I have no clue what changed.