> x2goserver-4.1.0.0-0.0x2go1.0.git20171105.1438.heuler.fc26.x86_64

Okay, so in that case you probably haven't set the loglevel to debug in
/etc/x2go/x2goserver.conf :

Nope been debug for a while now:

[log]

# possible levels are: emerg, alert, crit, err, warning, notice, info, debug

loglevel=debug