Here’s my Document in Outline View, no filters:
And here’s what it looks like when switched to G-B-Project view. Sort types are “none” and “none” so I expect the order of the Project Groups to be the same as they appear in the Outline. Note that 2021Q3 is out of order (the rest appear fine):
I can’t really figure out why this one Project is misordered; it might be related to containing all complete items vs. a mixture of complete / incomplete. It also may be mirror-related, although all these Projects contain mirrors.