the title says it basically:

when i make someone join spectators using "/spec user", there´s no message on the server saying "xy joined the spectators", and also, when i check the lfsworld progress window right after it, it doesnt show him spectating.

not a lfsw bug (/spec command is an internal LFS one, not related to lfsw)

ok, sry. I was more focussed on the missing "spectating" status in the lfsw progress window then the actual cause

Such a string seems to be missing within LFS. Perhaps a message to let the spectated racer know what happened to him would be in place.