STM32WB5MMG RTC only running when MCU is active

[Name]

Hello,

I am developing a Zigbee SED application on the STM32WB5MMG in which I need to use the RTCs timestamps for logging. VBAT is connected to 3.3V and LSE is used. My expectation is, that the RTC keeps running while Zigbee Sleepy End Device is not active (e.g. in STOP mode) such that the time the controller is sleepy the RTC still keeps track of time. The actual result is, that the RTC only continues counting only when the device active which results in the log containing useless timestamps. What might be the issue here?

The RTC timestamps look close to this with wakeup every 5 seconds:
01-01-2000T00:00:01
01-01-2000T00:00:02
01-01-2000T00:00:03

Expected result:
01-01-2000T00:00:01
01-01-2000T00:00:06
01-01-2000T00:00:11

Best regards

[Name]

Any ideas?

[STTwo-32]

Hello @Name 

Have you seen the same behavior will using the RTC timestamp without the implementation of Zigbee.

Best Regards.

STTwo-32