This morning i watched my gps track and did remember me when a macrodroid time trigger played a sound, and it was 4,5 min to late. And later i watched at the phone and it was 1 min to late. It seems MD have it's own clock defined by the moon. I guess i need to reactivate my alarms made by the Samsung Galaxy Clock Software.
Hardware: Samsung Galaxy XCover 4 (SM-G390F) OS: Android 7.0 Noroot
MacroDroid requests the exact time you specify. It is your Samsung that does what the hell it likes with regards to letting the device wakeup.
Please look at configuring the trigger and you will see an option to use alarm clock option. You will need to use this (and yes it will display an alarm symbol on your notification bar)