Ipsec version: Linux strongSwan U5.9.8/K6.1.0-kali5-amd64 Leftauth=xauth #no difference in using xauth-eap or xauth-hydrid
so the server is verified by certificate (it is exported from smart console and imported to strongswan) und the client with username:password.
The error looks like a PSK would not match but xauth-hybrid should be used. Tested with Windows Version of Checkpoint Endpoint Software. I try to connect to a r81.10 gateway using a linux distribution with strongswan.