Client isolation on SSL VPN network?

Hi,

we've been using SSL VPN on XG for a long time now and it works good. But now we came across the issue that we can't see other SSL VPN users. So it is not a problem from SSL VPN to LAN but inside the VPN network. A ping to a device resolves the right ip address but the ping itself as well as other services don't work. They work when we are all in the LAN. So is client isolation active in the SSL VPN network? Which settings need to be ajusted?

A rule which allows traffic from VPN to VPN is already active.