I have had the same problem you have, and it seems like its pretty common for the WD Live. I have sent this answer in several threads, but YOU might not notice it since you might not follow those threads.
I was able to get access to mine by going to the Windows File Explorer. Right click on Network. Select “Connect to Network Station”. I selected the drive adress “\mybook” (Yours may have a different adress) and selected a drive name such as z: and used my login credentials after checking both boxes.
It may not work for you, but it did for me. My WD drive denies connection at random frequencies, and it seems like it does it if a certain number of units has connected to it.
Will try to avoid WD in the future since this issue has been unsolved for since I bought it about a decade ago. Which is the best thing about the WD Live. It lives for a long time. Mine has been running since I bought it, with no other issues than one of the most important features for a network drive. Being able to connect to it.