Xavier is not communicating with another device via canbus interface

Hi eeren,
You cannot connect CAN0 to CAN1 without transceiver. Only CAN0_TX to CAN0_RX is possible.
For communication with other device: can you see if bitrates set are same for both the CAN nodes on the bus. You can check Xavier bitrate from ip -d -s link show can0 if you made can0 up on network.
Also, provide dmesg error logs to us.

Thanks,
Shubhi