Why I can not access directly connected NEs?

Maybe I have a simple question or maybe not.
I have a RB1200 and I have different ports in use with different subnetworks.
Why I can not connect to an other NE, which is directly connected to the RB on a different port?

The Network is listed in the routes with DAC and reachable.
But I can not connect with the device.
What can be the reason? Did I missed something to configure?
routes.JPG
Interface and Mangle.JPG

To make it more transparent.
I’m entering from the 10.10.4.0 Network and want to enter the GUI of the antennas in the 10.10.3.0. Network, which is blocked by the RB. The user traffic in both Networks is working well.

I think it is a Problem with the mangle rules, but I do not know how to overcome this Problem.
Any help please?

no answer…
Please help me out!