InDesign Loses Its' File Path Randomly

I've noticed something weird with InDesign.
Sometimes it loses the location of the previously saved document.

When this happens, the path that it chooses seems to be random.

An example would be if lets say I save a file called file001.indd in a folder called 100047.

If I go back to that folder the next day and make a revision to the file, sometimes the file save location is not pointing at the folder 100047.  It seems to pick a random location.  So if I'm not paying close attenton, I may save my file thinking its' location will be in the same folder, however it will be pointing at the random folder location. This happens when saving or exporting out to PDF.

This does not always happen, however it does happen on a regular basis.

Does anyone know the cause of this?