Hi Purifier

This is because you have two Bed selling units in the shop.
The first one is enough to satisfy the demand in that shop, so the second one never gets to sell anything and doesnt lvlup.

Later on, when demand increases, the second one then starts selling beds. Once that happens, it will begin to lvlup

hmm weird... a few years further now and the boxes start to lvl/train....

quick update, my idea doesnt work :p

In another furniture store in another city the demand for beds is pretty low still, but the purchase/sales boxes do lvl...

Below is a cropped picture of 2 of my furniture stores.

As you can see all but the righttop side purchase and sales boxes are lvled to 3/4. (marked with yellow)
I noticed those 2 boxes on both stores not leveling. (not marked :p)
I deleted and replaced the boxes but to no avail.
But suddenly the store on the left started to lvl those boxes, but no the boxes in the right store (marked with red).

An idea came up as follow: The boxes lvl according to the supply/demand lvls. And with the demand of the left store a bit higher then the one on the right it started to lvl those boxes. (marked with light blue)

This idea is far reached cus the first 2 purchase/sales boxes in both stores did lvl to 4 already..
David if you can relay this to the dev team, maybe they can say if this is intendend in the engine or it is a bug.

These are the only 2 stores i have training on atm, but ill start training in my other stores aswell to see if the same is happening... the Demand in those are pretty low, so according to my idea the boxes shouldnt lvl..... ill keep you informed

If needed i can send you the safegame...