Hi emb01_jtronix,
Masmiseim's checking is valuable.
1. you need to check your LPC side, whether it has the CAN transceiver or not.
2. You need to check two board is using the same bitrate in the CAN bus
3. If you don't have two MIMXRT1020-EVK board, you also can use another CAN NODE, take an example, the PC CAN testing tool with the CAN Analyzer tool, this tool will be another CAN node, and can send or receive data from your RT1020-EVK board.
Wish it helps you!
Best Regards,
Kerry