Cant communicate with Zubax GNSS 2 using Can bus

I am trying to communicate with Zubax GNSS 2 using can bus, but can transmission failure occurs.
When I execute uavcan status in QGroundControl, I saw following informations:
UAVCAN node status:
Internal failures: 0
Transfer errors: 0
RX Transfers: 0
TX Transfers:1765
Can1 status:
HW errors:0
IO errors:0
RX frames: 170191
TX frames:1765

What could be the main reason of difference between Can1 RX frames count and UAVCAN node RX Transfer count ?