Do you follow every steps listed above and run w/o errors?
Could you share the full dmesg for further check?
[ 450.185120] mttcan c310000.mttcan can0: Acknowledgement Error Detected
[ 450.185229] mttcan c310000.mttcan can0: IR 0x8000000 PSR 0x71b
I’ve found another user having the similar issue as yours.
Xavier cansend cannot update data - #6 by darmaji998
Are you using SH65HVD230 for both your CAN transceivers?
Could you use the following command instead to setup can0and can1
sudo ip link set can0 up can0 bitrate 1000000
sudo ip link set can1 up can1 bitrate 1000000