Orphaned folders (can't be deleted?)

My EX4100 has 3 folders (that I must have created long ago) that show up in the EX4100’s Web File Viewer, but not in either my Mac’s finder or my Windows laptop’s file explorer. Each folder contains a single file. I’d like to delete all the folders (and their contents), but can’t figure out how to. That’s because the action buttons – including delete – in the Web File Viewer remain grayed out when any of these folders or the files they contain are highlighted. (And because I can’t see them in Fiinder/file explorer.)

Note: several Shares that I’ve created also show up in the Web File Viewer, and for them and their contents, the action buttons are active (that is, not grayed out).

Any suggestions on how I can get rid of these folders (and their contents)?

(I’m guessing I need to use SSH [via this, and this], but it’s not something I’ve used before, so I’m not sure…)

Many thanks! Steve

p.s.: I already posted this query to the My Cloud EX4 Forum, but no replies. Apologies for the re-post, but I’m really hoping someone might have a suggestion for me.