No longer able to create share link for the backup files

The files in the Backup feature are no longer able to create the share link after the data is migrated from my old MacBook to the new MacBook.

I am using the Backup feature to back up the above 3 folders. But now, those files in the 3 folders are no longer having the option to let me create the share link when right-clicking those files. Also, those folders are weird, they should be Alias and not a real folder. And there doesn't have a hidden folder of my Mac's data in the Dropbox folder. I remember those 3 folders are using the Alias (the real location should be inside the Dropbox folder and Mac's backup folder), and there is having a backup folder for the Mac in the Dropbox but now all gone.

Moreover, those 3 folders are not available to delete them. I was trying to delete those 3 folders and let the Dropbox app recreate those folders, but It is not successful. Those 3 folders are no option to "Move to Bin" and MacOS will recreate them immediately even I use the command to delete them on the Terminal.

Does anyone have the same experience how to solve it?