Dropbox folder aliases don't work as expected

Perhaps this is expected behavior but I didn't expect it 😟

I have long had aliases for folders in Dropbox placed in other (non Dropbox) folders, for ease of navigation. So I have two such folder aliases in a third folder (this one in my User folder). When I click on each of these folder aliases (in column view), I see the contents of the folders, each item with a green check (most of my Dropbox files are set for Offline viewing and have downloaded). But when I tried to drag a file from one of the folder aliases to the other, nothing happened! Normally, the dragged file would immediately move to the other folder, but it did not. In addition, when I tried to drag another file from the desktop (which is not backed up, BTW, in Dropbox) to the folder alias, it would not move; it just stayed on the desktop. If I clicked on the folder alias, so that the contents of the folder were visible, and dragged the file to the list, it moved as expected. To move the first file from folder to folder, I had to first move it to the desktop (confirming that I wanted to move the folder out of Dropbox), click on the second folder alias to reveal the contents, and then drag it to the list (not the alias--that doesn't work!)

I did go to Dropbox and found the two folders referenced by alias and it was easy to move a file from one folder to the other, but I don't know why it wouldn't work to move files into Dropbox folders referenced by alias???? Thanks!