What the! That selection circle?

All of a sudden some of my units have strange selection circle behavior. They somehow follew terrain height.

Of course they are all set at 0 height.

I looked in gameplay constant and I don't think I have changed anything regardng this weird effect.

Any idea on what might be going on?

What about, in unit object editor properties -
Art - Selection Circle - Height
-? That should be it.

Found the eak! It was simply that some of the units had selection circle on water on. I turned it off and all is back to normal.