command delete not finding rejected photos

[crackerjack*]

I have updated to the newest Lightroom Classic - 9.3. Now when I reject photos (click x) and then use the command delete option to delete photos, I get a message saying 'there were no rejected photos to delete" I tried deleting preferences - didn't help. I uninstalled Lightroom (chose not to keep preferences) and reinstalled, same thing happening. If I click the 'black' flag filter (which I thought was rejected photos?) It doesn't find any. If I navigate to the folder where I have the rejected photos, I can see that there are several rejected. Any suggestions? 

UPDATE - I navigated to the actual folder on my external hard drive and synchronized the folder - that seems to have fixed it. 

I had moved the folder from my hard drive to my external hard drive - and although it appeared that the images were not 'missing'  I guess it was not pointing to the right location. 

[JohanElzenga]

Images do not show as 'missing' if you generated smart previews for them. If you want to move a folder to another drive, then either do so from within the Lightroom folder panel, or 'reconnect' the folder by right-clicking on the folder in Lightroom and choosing 'Update Folder Location' (or 'Find Missing Folder' if you already deleted it from the original location). Do not use 'Synchronize Folder' because that will make you lose all your edits and added metadata.