Folders on external HDD not showing up when switching between mac and pc

[Aussie Bubbles]

I save all my photo's on an external hard-drive and import them into lightroom.  I switch between mac/pc laptop.

HDD file format is ExFAT

Folders that I edited on my mac laptop are not showing up on my PC laptop and vice versa.  There seem to be lots a questions around similar issues and after having read through the many of the discussions I still can't get an answer (maybe I'm not reading enough of them).

I always save the catalog file when shutting down.

Does anyone know how I can recover the edits on either laptop or have an explanation as to what I'm doing wrong?

[Just Shoot Me · Accepted solution]

LR is a Database, Catalog, system. If an image is not in the Catalog, a Record made in the database for that image, it won't show up in LR. Are you storing the catalog on that external drive or just the images.