Slitherine

Not sure if this issue has been reported already.
So with my new barracks I built some units as Saba to add to existing armies. No problem there, they came out with their little one star of experience and I transferred them into the armies where they promptly lost their star of experience. Splitting them back out of the armies the star came back, back in went away!
So what is the deal? Bug or an as yet unexplained rule whereby their experience doesn't count in an army until they have proven themselves?

When you merge a unit into a stack with a General, the unit loses a star until it is "integrated" into the team the next turn. When you add or change the General, then all the units lose a star until he gets up to speed.