Orel20 CAN disconnection issue

when connecting the babel to the orel20, applying the 127 local id node and starting the dynamic node allocation server. I could see my orel20 sometimes, but it disappears erratically. the second CAN1 port is connected to a 120ohm resistor.

Thanks in advance for your help

You may want to check if termination resistor is activated on Babel side.
There is no need to use a physical resistor in this case as there is 120R resistor on the PCB already and it can be activated from UAVCAN GUI TOOL

my bad, the problem was because I used two different uavcan GUI session at the same time.