why can't I access my postgres from remote?

I have a Postgres 10.3 Server installed on an Ubuntu Server.

I did the necessary settings, which always had been enough to be able to access it from PGAdmin from my Laptop, but this time it doesn't work.

I tried the following steps:

listen_addresses = '*'
host all all 0.0.0.0/0 trust
ufw allow 5432
Postgresql restarted
Server rebooted
Server pinged with success
Restarted the VPN-Client
direct IP instead of VPN-IP
disabled IPTABLES

Locally I can connect to the server, but remote is still not working.

When I try to connect, it doesn't seem, that postgres is blocking it, but something before:

Unable to connect to server:

could not connect to server: Connection timed out (0x0000274C/10060)
Is the server running on host "10.8.0.50" and accepting
TCP/IP connections on port 5432?

What can be the reason?

When the server were set up, Plesk were installed.

Plesk had an own firewall, which denied the connection. After allowing it, it worked flawless.