92 Buick Regal; Stop light not working

My driver's side stop light is not working.
I've taken it to the shop and gotten tons of wires replaced and the mechanic is stating that my multifunction switch is malfuntioning. I'm wondering if this is really the case because my right side stop light is working. All the bulbs have been replaced, and all the wiring is good.

So I'm wondering, does the multifunction switch have control over the stop lights, or the stoplight switch, or both?

Any ideas?

Do you have the multifunction switch (MFS) with the hazard warning switch on it as part of the same assembly? If so then the stop/brake lights goes through contacts of the MFS.

Do you have the multifunction switch (MFS) with the hazard warning switch on it as part of the same assembly?

Yeah, I'm assuming I do since the hazards are right on the steering column.

Thanks for the info. If it's a possibilty I'm sure its needed then. Just wanted to double check before I take it back to the mechanic.