IPSEC VPN up but no traffic

Hello all,

i'm having a strange issue with my IPsec connections. I'm on SFOS 18.0.0 EAP2 and:

One IPsec connecting from XG (10.100.10.1) to UTM (10.200.100.1). The Connection is up and running. UTM and all Clients behind it can reach XG and all devices behind.
XG can reach UTM and all devices behind the UTM.

But no client behind the XG can reach the UTM nor a client behind the UTM. I've never had this issue on 17.x. Is there a special configuration on 18.x?

I added the firewall rules manually and automatically.

Output "route -n":
10.200.100.0    0.0.0.0         255.255.255.0   U     0      0        0 ipsec0

Default routing Precedence:
1.  SD-WAN policy routes
2.  VPN routes
3.  Static routes

Somehow the XG is not routing the traffic from the Clients to the UTM.

Cheers,
Patrick