File sharing problem - the operation can’t be completed because the original item for “Folder Name” can’t be found.

I have a file called External Downloads. It's shared to allow guest access from my Mac Mini. It's on an external disk drive connected to the Mac Mini.

When I try to connect to it from my MacBook I get the error - 'The operation can’t be completed because the original item for “External Downloads” can’t be found.'

The folder appears in Finder. Other folders already shared or newly shared folders appear as well and can be accessed.

I've tried deleting and re-adding the folder on my MacMini but still get the same error. I can access the parent folder, also shared, and then go into External Downloads as well.

This is driving me crazy. Any suggestions?