The way Indesign navigates folders has become very inconsistent and is creating a lot of extra work. For the most part, they are not defined by the files themselves nor InDesign (historically it has been one of those two).
Now it is defined by the specific tool which is taking a lot of time extra navigating when switching between multiple projects or clients, and makes it very easy for files to end up in the wrong places. Below is a list of the how each tool is navigating.

File Save As:
a. New File: Last folder Indesign save to by any file
b. Existing indd file: The Files current location
c. Existing idml file: Last folder Indesign save to by any file (not it’s current location)

Export:
a. Same as file

b. Once anything is exported in any folder not the same as the file, it exports to the file’s last export location
If copying a file: Save As resets it the export option to a. Duplicating with finder or packaging the file does not.
C. If a new file has never been saved, it will follow the export rules of the last file InDesign used

Package: Last folder Indesign packaged to by any file.
Place: Last folder Indesign placed from by any file.
Relink: Last folder Indesign relinked from by any file
Data Merge Source: Uses export to define
Load Styles: Last folder Indesign loaded a style from
Import PDF Comments: Last folder Indesign attempted to place comments from, even if unsuccessful.

I am using InDesign 18.5 / Ventura 13.5.2 but behaved this was on Big Sur too