Ideas
Ok, so what is bugged are SHELVES, PEDESTALS and DISPLAYS (every kind of them from GTW), like these
If you place something in them and set it for sale, it's like sims will not see it and retail won't work (no purchase intent or anything) so sims will only chat, (the most simple way to find it is to open a bakery) so it should be a problem with the tuning of shelves that changed with last update. The moment you put for sale something that isn't in the shelves, like in a table or on the ground or a mannequin, sims will start acting ''normal'' (even buying items on the shelves, but not browsing in them, they just concetrate around the item that is NOT set on the shelves) like this
In the picture I set everything in the store for sale but sims concetrate in the thing (the toy on the countertop) and dont care about the items on the SHELVES, and if I delete that toy, retail won't work.
Oh my gosh thank you! I have been searching like crazy trying to figure out what was happening and this must be it. Deleting all the displays and putting stuff on the ground worked for me!