Western Digital HDDs not showing up in a docking station while others do?

Drives never show up in Windows Explorer. It would make no sense if they did.

Imagine, for example, if a drive with two partitions showed up in Windows Explorer and you double-clicked on it, which partition would it open? If you dragged a file to it, which partition would it go to?

Only mounted filesystems show in Windows Explorer. If a drive has no mounted filesystems, it does not, and should not, show up in Windows Explorer.