T1-Grundstücke, die von Märkten stammen, bringen keine Juwelen hervor?

So i have about 20 T1 class 2 single tile properties i bought when earth 2 came out and they give me lots jewels daily. Problem is i have purchased T1 single tile properties from other players over the last 6 months, about another 50 of them and they dont give out any jewels. Whats the issue there is it bugged?