Experiencing the same issue since installing Cottage Living + Update. I have zero mods, though have used some cheats (ignore gameplay unlocks entitlement, added traits/skills, motherlode). Anyway, I cannot sell excess seeds/produce from my inventory. I have not yet completed growing anything since this update/install to see if that produce can then be sold.
In case it helps anyone, I’ve had success selling using the multi select button in my inventory. Personally it seems like I’m only seeing this from non-planted extra herbs from seed packets, I was able to sell with multi select. I tested with a couple and could also sell if I dragged them onto the ground and then had my Sims spouse sell them.
