I am sending tagged packets to a node expecting tagged packets.
It took me ages to find the problem, however it appears the maximum VLAN number your RUT955 will handel ist 15.
Please confirm or deny that your system will handle VLANs greater than 15.
For example, 16, 20, 71, 171 and 717 do NOT work. 1, 2, 7, 10 and 15 do work.