I selected 10 photos to be exported to a folder on my hard drive but only one photo gets exported at a time. This did not happen until I upgraded to LightRoom Classic CC.
I have the same exact thing happen, and it clearly says all are selected, but when the export finishes, only the first photo in the selection shows up. I then will restart lightroom and sometimes my computer, and then the photos show up sometimes. I feel like this is a Finder problem (I'm on a Mac) or possibly communication between LR and Finder. Any help is much appreciated.
Having the same problem after upgrading to Lightroom Classic on MacOS. I highlight 34 photos to export as JPGs. The process starts and says that it's exporting 34 photos as the progress bar in the upper left slowly moves as usual. When the process finishes, only one JPG shows up in the folder.
I had this problem but it somehow resolved itself after restarting, so perhaps Finder-related as mentioned by others. Could also have been fixed by an update in either OS or Lr. Currently I'm at Mac OS 10.15 and Lightroom Classic 9.0 but I'm unsure of exactly what I had when problem occurred.