I've managed to reproduce the behaviour on the same server. It's something to do with tags, Control+Enter, Split view, and the space in the file name. To reproduce:

- Set sorting to Name.
- In a folder, create two files called:
Aaa .aaa (note the space)
aaa.aaa
They'll be shown with Aaa .aaa at the bottom.
- Copy these two files to another folder
- F8 to enter split screen view, and navigate to show one folder on the left, the other on the right.
- Tag both files in both folders.
- In the right pane, press Control-Enter to enter Tags-only mode
- Tab to move to the left pane
- Tab to move back to the right pane - now the order reverses, with Aaa .aaa at the top.

I suspect you might need CO-3H set to yes. I've got that whole section set to Yes, not sure what the defaults are.