@ When the documentation says "default administrator account" it does not say "domain" or local builtin on the server. Which does it mean?
Any user who is in Group "Administrators" be it local or domain should be fine.
@ Why? is there a known issue or is it just that it has not been tested?
I don't know all reasons but some things don't work unless you login as the Administrator user i.e. a user with Administrative privileges. What I have noticed and remember is that some WFA applications access the windows registry and a non-administrator user doesn't have the right for it.
WFA service by default runs using the Local account, and if the local account doesn't have all permissions , WFA functioning could be affected.
But I haven't tested much on this area.
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