On a new session (luckily for me, as I reverted to the previous save) I fiddled with old security formations on Mars, by showing all elements, and grouping 4 formations into a single one. The end result somehow was that I had the remaining formation with a 25k HQ leading another 25k HQ, which seems not very legit to me. But oh well ... Then it went worse.
I closed the window and reopened it, and Mars was only showing the header, and nothing else, although clicking on Mars showed all elements there, but without any formation.
I did not save as it was feeling very buggy. So my question is probably, do people encounter these organizational bugs in land units or not? This was the first time I did some reorg, and bam a bug, so I guess it's not ultra-rare?