Installer does not issue LE certificate
If server has multiple ip addresses and the hostname is NOT on the primary ip, the dns record check will fail.
Checking / creating certificate for px.myserver.de
Using certificate path /etc/letsencrypt/live/px.myserver.de
Server's public ip(s) (xx.yy.tt.aa, 111:222:333:444::1) not found in A/AAAA records for px.myserver.de: aa.bb.cc.dd,
Could not issue letsencrypt certificate, falling back to self-signed.
aa.bb.cc.dd is a failover ip but xx.yy.tt.aa the primary ip.