Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Nuvoton/NUC1xx_registers/INT/IRQ31_SRC#0x0
MCU IRQ31 (RTC) interrupt source identify
Bit2: 0 Bit1: 0 Bit0: RTC_INT
https://github.com/cmsis-svd/cmsis-svd-data