Tvheadend

If the option to forward EMM updates is checked, a NewCS server with a Irdeto card immediately logs "Bad request? rejecting..." upon login.
After that, and before the cwc keepalive (30 * 2 = 60s ) expires, if one tries to view an encrypted channel, no further communication is made between tvheadend and newcs (nothing logged in NewCS).
When the timeout expires, a disconnection is logged and a re-connection is issued, after which, the channels are descrambled fine; even switching between channels works fine and quickly, too.
When one stops viewing a channel and the connection enters the idle state, the same problem starts to appear again.
Actually, when the connection is idle, the tvheadend user gets disconnected by newcs every 1 minute and logs back in again.
If EMM updating is disabled, everything works ok; no error messages on logs whatsoever.
Please note that is is definitely not a server problem, since the server works fine with other clients (even with cccam with tvheadend connectind through camd.socket to it)