One wakealarm does not work (out of 5) in OMV 5

I use OMV 5. I need the system to startup every weekday at 07:00 and auto-shutdown at 21:30. I have scheduled wakealarms for the first case and "Scheduled jobs" in Power Management for the latter. All days work as expected, except for Mondays! The system does not auto-wake every Monday. It does so in all other days. Here is the output of "cat /etc/wakealarm.conf":

# This file is auto-generated by openmediavault (https://www.openmediavault.org)
# WARNING: Do not edit this file, your changes will get lost.

# m h dom mon dow

0 7 * * 1
0 7 * * 2
0 7 * * 3
0 7 * * 4
0 7 * * 5

I also attach the screenshots of the wakealarms and the shutdown settings.

Few weeks ago, I had the server to wake up on Tuesday - Friday, and to shutdown on Monday - Thursday, so that it remains open at weekends. Then, everything was working fine. Since it is not necessary any more to be open at the weekends, I added a shutdown at Friday, and a wakealarm on Monday. The latter never works! I tried to delete it and create again, and also to delete all wakealarms and create all of them from the beginning. The result is the same: everything works fine, except for the Monday wakeup!

Any ideas? Thank you!!

Since I have tried all I have thought of, I tried to wake and shutdown the server at Saturday and Sunday for a couple of hours. I have not change anything else. And now, today, Monday, it started as expected!!! I cannot think of why this behaviour.

For next week, I will try to disable the Saturday one, just to see what is going to happen. I will report back.

If you have any explanation for this strange behaviour, please let me know.