Catalog thumbnails do not update when moving folders

I'm moving folders of photos from Elements' folders panel 'view as tree'. I'm dragging a folder of photos from an older NAS to a newer NAS. The photos move fine (the folder is moved in Windows file system correctly), however the thumbnails in Element's catalog do not update. The folder still shows in the old location from within Elements but now all the thumbnails are missing their source file. When I click one of the photos, I have to manually browse to find the new source and reconnect the thumbnail with the photo in its new location. When I do that for one of the photos in the selected folder, the rest of the thumbnails are connected and the catalog is updated (the catalog shows the folder location under the new NAS in the folder tree and no longer in the old NAS). This is incredibly frustating and manual work since I have 20 years of photos and my file system is by day (YYYY MM DD). So I have on average 300 folders per year--that's 6000 folders to manually move and then correct missing files. I'm using the latest Windows 10 OS and am on Adobe Premier Elements 2019. My Elements catalog is a bit over 100,000 photos and I was unable top backup the catalog and restore in the new NAS (Elements kept crashing) so I have to resort to manual moves. Any thoughts on what's causing the thumbnails in the catalog to not update when manually moving folders?