WOL don't work for 20 of 30 identical installed computers

Hi,

I have installed 30 identical computers with the same image of Win10. (NIC: Realtek PCIe GBE Family Controller) Only 10 wake up on a magic paket from a WOL-Server. What I've done on some computers to resolve this:

update BIOS to the latest

update NIC-driver latest 6/2018
configure "private" instead public Network

BIOS is WOL enabled.

Driver,  tab advanced:

disabled 'Green Ethernet'

enabled 'Wake on magic packet'

enabled 'Wake on pattern match'

Not speed down at 'Wol and shutdown linkspeed'

No success. Someone have an idea?

Thanks Heiko