Find and remove odd odor in new room

The set up:

I enclosed the part of the garage to make an office/man cave. I had a Mr. Slim installed to control the temperature. The space is 10' X 20'. No carpet. There are three desks, three chairs, a couch, an upright freezer, 7 computers, and a few guns. Your basic geek-ed out man cave. 😉

The issue:

There is an odd lingering smell.

The Smell:

It's a Sweet + foot smell. I don't know how else to describe it. It's not repulsive, but not great. It first hits you when you enter the room. My carpet cleaning friend said it's not something he has come across before.

I asked my wife to describe the smell. She said "Stale locker room with a hint of chocolate chip cookie."

What I have already done:

I fist suspected Mr. Slim. I checked the drainage line and found that is was not draining correctly. I ran a new pipe. Then let the humidifier run for a day and made sure there was a nice flow of water at the end of the pipe and no water in the collection tray. There isn't any bulging paint or warped baseboards under Mr. Slim.

I used a can of Evap Foam no rinse cleaner on the Mr. Slim coil. So I don't think Mr. Slim is the issue.

I found a Kenmore 85500 Air Purifier and have been letting it run with an new filter for about 2 weeks. The smell is less intense but still there.

I had all the same furniture in the old man cave and didn't have the smell.

The question:

Any other ideas on ridding my man cave of this smell?