Traveller family only adds 1 settler

I had a few times today that adding a Traveller family added only 1 settler. Also in the Star menu, it said: traverller family and under 1. The first time I thought I selected the wrong image, but I got the same problem a second time. It could be that my settler limit was almost reached at that time. Now that I have increased my settler limit, it seems to work again.

If you do not have the cap for the whole family the remaining settlers will return to your starmenu.
So no settler was lost. (or at least shouldnt be)