Is there a watchdog timer for M0. I am putting the uC to sleep and wake up once a minute to take a reading from the BME 280, but very randomly the uC will hang at wakeup time.
My take would be to fix the issue rather than apply a bandaid, but see this article about WDT on SAMD21:
https://eugeniopace.org/arduino/resiliency/2020/05/11/Using-a-Watchdog-to-fix-all-issues.html