Even if the irq is disabled, the HAL_SuspendTick is needed to enter stop mode properly, like this is done for sleep mode
when the freezing the RTC during debug with LL_DBGMCU_APB1_GRP1_FreezePeriph(LL_DBGMCU_APB1_GRP1_RTC_STOP);
else the Alarm is not exiting the system from deepSleep (STPOP01/2) even if the alarm flag is set.
Even if the irq is disabled, the HAL_SuspendTick is needed to enter stop mode properly, like this is done for sleep mode when the freezing the RTC during debug with LL_DBGMCU_APB1_GRP1_FreezePeriph(LL_DBGMCU_APB1_GRP1_RTC_STOP); else the Alarm is not exiting the system from deepSleep (STPOP01/2) even if the alarm flag is set.