Not sure when this started happening, but as above - if I try to make a new folder in the save dialog, it fails to rename. I can write files fine to the created folder, I just have to manually rename in finder.
In the window, you can change the name by pressing the F2 key.
I don’t know if the problem you asked is a problem with the mouse (double click error) blender.
If there is a problem with the blender, you can use factory initialization (back up the existing configuration file)
I know that’s how you should be able to rename folders, but it’s just that it doesn’t work, and gives the error above.