Ideas
My game is updated, not using any cc or mods (I am on PC). This is the situation on a nightclub I made. I am aware of this bug before the recent patch. So far I don't experience any difference after the new patch. This is after my sim is in the lot for several hours.
I try again in Windenburg bar, I immediately click on the bartender and the option is available. I haven't done any testing other than this.
PS. I only have City Living, Get Together, Tiny Living, SP and kits The Sims gave away for free.
I have this bug since a year and a half, I have 3000 hours of gameplay, sometimes it happens, sometimes it works fine. It can happen in bars, cocktail bars or at parties at home when you hire a bartender who can do nothing or be behind the bar with no option to order a drink.