Functioning My Book no longer appears in file explorer as a network drive

How can i get My Book to appear in file explorer again? It is plugged via ethernet cable directly to router. Until recently, it appeared in the file explorer of my PC under network drives but no longer shows. I’ve always dragged new files to it via file explorer but can’t now.
It does show in file explorer with an icon under ‘storage’ but not as one of my accessible drives.
I know it is functioning as my Sonos speaker can still play music files from this drive.