First, I am sorry for my bad English.
WOL doesn't work normally on HP Microserver gen 7 (N36L, N40L, N54L) with DSM 6.2.3 (works on DSM 6.1.7 and earlier). It's a problem with Broadcom Ethernet adapter (network card) and drivers for it.
HP Microserver gen 7 (N36L, N40L, N54L) has a problem with WOL on all Linux OS.
Look at these articles:
https://blog.frankleonhardt.com/2013/freebsd-wake-on-lan-and-hp-microservers-wol-compatible-ethernet/
https://www.truenas.com/community/threads/wol-on-hp-microservers.77068/
https://community.hpe.com/t5/ProLiant-Servers-Netservers/Proliant-N36L-microserver-WOL-wake-on-lan-not-working/td-p/2361057
https://forum.openmediavault.org/index.php?thread/16814-how-do-i-get-wake-on-lan-running-on-hp-microserver-n54l-working/
https://n40l.fandom.com/wiki/Wake-on-Lan_(WOL)
You need to disable broadcom network adapter in bios and install another network adapter.
I bought an intel Ethernet adapter EXPI9301CT, then I installed it in hp microserver gen7 N40L, and WOL on DSM 6.2.3 is working... on native MAC, without change MAC address.
Look also at this discuss: https://xpenology.com/forum/topic/701-microserver-n54l/page/48/