PCoIP connection error with 3040

Hello
this is the first time we are using ThinOS thin clients.
we are trying to connect from Wyse 3040 (PCoIP version) to an on-premise Teradici Cloud Accses Graphic Agent and getting an error "The netwrok connection has been lost (UDP).
now, we are inside the LAN, so no ports should be blocked, and the Windows firewall on the Agent side is disabled.
also, we have no problem to connect to the same agent using Dell Zero clients and using Cloud Accses software.
our setup is super simple. no broker at all.
so i have choose "none" on the broker setup, and on the Connect Manager i have created a new PCoIP connection, and typed the IP of the Agent.
any idea what i am missing?

info on the 3040:

Build name: AP10Q_wnos

Bios Name: A10O_bios.bin

Teradici PCoIP: 2.9.51608

Build Version: 8.6.013

Bios Version: 1.2.5