Apache2 / install-letsencrypt-cert.sh not working

Got yome issues with install-letsencrypt-cert.sh-Script on a server runnig apache2 (most issues here aim on ngnix):

Challenge failed for domain my.domain.com
http-01 challenge for my.domain.com
Cleaning up challenges
Some challenges have failed.

 - The following errors were reported by the server:

   Domain: my.domain.com
   Type:   unauthorized
   Detail: Invalid response from
   [123.456.789.012]: "<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML
   2.0//EN\">\n<html><head>\n<title>404 Not
   Found</title>\n</head><body>\n<h1>Not Found</h1>\n<p"

Followed Quick-Install Guide, everything seems to work pretty well (Domain ist reachable, working DNS A record). Except LE.

Any ideas? Thank for your effort!


PS: Debian Buster.

Issue@Github: https://github.com/jitsi/jitsi-meet/issues/5434