on my side, I was confronted to the issue 2 times, on windows 10 & today on windows 11, and I managed to find again how to do it.
step 1 is on the registry editor (start menu > type "reg" to see it appearing. > allow it to make changes on your computer)
Go to HKEY_USERS.DEFAULT\Control Panel\Keyboard, double-click on Keyboard
Set 0 to disable the NumLock key at the start
Set 2 to enable the NumLock key at the start
Go to HKEY_CURRENT_USERS\Control Panel\Keyboard, double-click on Keyboard
Set 0 to disable the NumLock key at the start
Set 2 to enable the NumLock key at the start
step 2 is using the microsoft powertoys. (if you don't have it, find it on the microsoft store, and install it)
once installed, open it (type powertoys in the start menu), and look for "keyboard manager".
to disable the NumLock key at the start,
on the left side, select "NumLock", on the right side, select "disable"
numlock disable on keyboard manager
to enable the NumLock key at the start,
on the left side, select "NumLock", on the right side, select "select"
numlock enable on keyboard manager