VPN web mode - connection to rds FARM

Hi,

We've recently upgraded or 100D to firmware 5.6

When users uses SSL VPN Web mode to connect to our RDS farm they are disconnected.

the "quick connection" rdp in the web portal is configured with one IP of our 6 RDS servers.

when i am redirected to another server i'm getting disconnected. when i'm not redirected it works...

is this a bug or misconfiguration? Someone knows how to solve this?

THANKS!