Group tree is currently not very robust. I am aware of bugs with the with lines and order as well but I never saw this one myself. In this case, do you know where the shift come from? What about the groups above? Best would be to find a way to reproduce it.

I don't know what caused it. I haven't had any luck reproducing it yet: I'll report back if I have more luck.

In this case, the top few groups were fine. The shift started on one heavily stacked group (the top layer is just cut off in that screenshot). All groups from that one down behave in the same way. The bottom two groups didn't have the icons at all.