Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Nuvoton/NUC1xx_registers/INT/IRQ20_SRC#0x0
MCU IRQ20 (CAN0) interrupt source identify
Bit2: 0 Bit1: 0 Bit0: CAN0_INT
https://github.com/cmsis-svd/cmsis-svd-data