Well, maybe it becomes an error if you made a reservation once and fail. I guess you need to backtrack, load your past saved game. Then retry the reservation at noon. Or... maybe we have to wait for the next update.
Viewing post in Agent17 (18+ Adult Game) comments
Ok I figured it out.
After you reserve an appointment on your computer you have to quickly get to downtown and you will see then you will see massage parlour. I noticed that after a second the option disappears so thats the bug that was preventing me from seeing the option in the first place.
(Also I did this in the morning)