I think, unfortunately, the matter is not so simple.
In my case, HP Microserver N54L, new installation with DS3615sx (bromolow) DSM 6.2.3 25426 update 3
with Jun's loader 1.03b and internal HP-N54L broadcom network adapter:
WOL and the Schedule boot up/down works fine. :-)
Just tested again, no problems.
I used this guide, post 81927 [--> script path for 6.2.3 is now: /usr/local/etc/rc.d/ or --> via Control Panel/Task Scheduler/ as root/bootscript]:
And before, for my very old N54L, at least this (are there newer ones?) firmware update for the internal HP NxxL microserver NIC
(unzip and installed via Windows boot stick ...):
HP-NxxL_nic.zip
(sorry, I still have to search where I found the update, could have been via:
https://www.broadcom.com/support/download-search?pf=Ethernet+Controllers&pg=Ethernet+Connectivity%2C+Switching%2C+and+PHYs
or could have been via
https://www.hardwareluxx.de/community/threads/hp-proliant-n36l-n40l-n54l-microserver.752079/
or ? - But you should be able to find newer nic firmware directly at HP...)
If this does not help, you should check your bios settings again.
HP-NxxL_nic.zip