RTC of smt32F103C8T6 is not incrementing time seconds while VBAT is connected to a 3v coin cell on VDD cut-off, but it only retains the last value but not increasing.

[ashutamar]

RTC code is not working properly while VBAT is connected to a 3v coin cell, it only retains time from the last value but not incrementing as the time increases please let us know what's wrong with the code

I'm following this below link

https://www.micropeta.com/video46

I made code using STM32cudeMX code is attached below

Thank you in advance!

[waclawek.jan]

LSI is in VDD domain, i.e. it is not running from VBAT when mcu is powered down.

JW