Only group who was owning the land is mine, I am the owner. There are 2 members beside me in the group, they are my alts.
I have now only 1024 sq.m land, so I tried to manually update the tier as it should be done. Well, it seems that it doesn't allow me to do that. It shows only my higher tier box available or even higer ones.
So, maybe I should wait and see if there is some major bug in the system who delays this all for me...