Timeout during connect (likely firewall problem)

This error is a "Timeout". Meaning the Let's Encrypt server could not reach your domain.

Your examples using curl showed a 404 and 200 response. Both of those were successful connects just with different reply. Neither is a timeout. Are you sure you were testing from outside your network?

The Let's Debug test site is often helpful to debug

Without further details there is not much to say. A timeout is most often a firewall issue