What to run
Use Port Check. The result is from Cloudflare.
How to read the result
Timeout means no completed handshake from Cloudflare in time.
Closed, filtered, and blackholed look the same.
Do not write "closed" unless you got an active refusal and the page says so.
What to open next
Open DNS Lookup to confirm the host resolves to a public address before you retry. DNS Lookup is DNS-over-HTTPS from the browser and does not follow CNAMEs.