I upgraded from 17.1 to 19.1 using the apt installer. Everything seemed to work fine until I checked from another computer and discovered that all web pages on my server were being redirected to egroupware. I used to access egroupware by using the address www.mydomain.com/egroupware and that still works. When I go to www.mydomain.com it redirects to egroupware. Specifying index.html, www.mydomain.com/index.html, seems to work, but is inconvenient for users that have the site bookmarked. Not really sure on how to sart to unwind that.
Debian 10 all updates current.