Yes, good catch. I thought your dashboard is inside a life system. CAN needs 120 Ohm termination resistors on each end. Close Jumper J1 and add another one at the other end. I doubt there is a resistor on the dashboard because CAN only needs two and usually has many more nodes.
Then please do the test described in reply #3. First just the module with jumper 1 closed and another at the end of your CAN bus. Send one message. It should be repeated continuously. Measure the CAN bitrate with your oscilloscope and confirm it is 50kbits/s.
Then connect the dashboard you should see the CAN message you send is no longer repeated because the dashboard acknowledges the message as valid. This is a CAN hardware function. All active nodes will acknowledge any valid CAN message.