IPsec - connection failed

Migo

Hello,
I tried to establish an IPsec VPN connection from my Win10 Laptop to a pfsense (2.5.2-RELEASE (amd64 - GX-412TC SOC) - FreeBSD 12.2-STABLE) cascaded behind a router (Fritzbox Cable 6660 ) following the manual and this guideline: https://administrator.de/knowledge/ipsec-vpn-mobile-benutzer-pfsense-firewall-einrichten-337198.html
The connection failed with the hint "connection could not be established - no response of remote server".
The Status\Systems Logs\IPsec shows that there is an activity giving the hint that IPsec is doing something - but there is no hint of any connectivity.
I know that I did not provide much bachground information so far but I just need some help to start the troubleshooting. So first of all I have 2 questions:

The log Status\Systems Logs\IPsec still shows activity even there is no tried access from my VPN client

and

There is only information like: "charon 73028 08[CFG] vici client 250 requests: load-cert"
-> means no "charon 0x [IKE] IKE_SA ..." or "charon 0x [IKE] CHILD_SA ..." showing phase 1 or phase 2 successful established - only "charon 0x [CFG]"-lines

How can the log information be interpreted and how can I start the troubleshoot?
(a link to similiar problems just discussed in the forum would also be highly appriciated)

Many thanks in advance
Cheers Migo