LrC does not see photos on external hard drive
I am attempting to move my Lightroom Photo Library to an external hard drive. I initially followed Scott Kelby's instructions from his Simplified Lightroom Image Management video, moving the LPL to the external drive from within LrC. However, once that was done the LPL files no longer showed in LrC and LrC did not show (recognize) the external HD (??).
Searching for a fix here I found this advice:
Using Finder or Explorer, copy (drag n drop) the desired top-most folder from your internal drive to your external drive. Then in Lightroom, go to the Folders panel in the Library, right-click on the top-most folder that you copied, select "update folder location", navigate to your external drive. LR will update all the files and folders that you moved. Doing the actual file copy outside of LR is both faster and safer.
I like faster, safer, and copy so I moved the LPL back to my computer (Mac OS Monterey) HD where it was when I started. From within LrC all looked the same as it was before I started, so satisfied that I was back to ground zero, I copied the top most folder (outside of LrC) to the external HD (all worked fine), then in LrC I updated the folder location by navigating to the external HD. Now LrC "sees" the external HD, the total number of images next to the name of the external HD is correct, but all of the nested image folders have question marks on them and when I select a given folder LrC shows the images within, but won't show the images in some other folders. I checked on the external HD and the images that are not showing in LrC are indeed there (as well as the ones that DO show on LrC). All images are also still on my internal HD, as far as I can tell (which I would expect, given that I did a copy).
At this point I need to raise the white flag and call for help. What do I do to fix this? Thanks so much!