The My Passport drive was accessible and functioning properly approximately 2 months ago on my old 2009 iMac running OS X El Capitan. Please note that I have connected the 3TB device into the same USB port on this iMac as the one I have currently plugged the My Passport into, and the USB port functions correctly with the 3TB device. You can that a different Western Digital device is connected correctly, it is a 3TB device that is formatted as 2 volumes, one for regular use, and one used specifically for Time Machine Backups.
I am including a screenshot of Disk Utility, where you can see that nothing appears for the device.
When connecting it to the iMac, it spins on, like it should, and the tiny light comes on, but nothing happens on the iMac to actually recognize the device. There is no error to capture in a screen shot, because the device is not recognized at all. Since I submitted my Incident, I have upgraded my iMac to macOS Big Sur version 11.3. Maybe someone else has seen this issue and might be able to help! I’m pasting below all of the troubleshooting steps I performed based on my interactions with WD Customer Support. Since my device reached End of Support in 2013, there really isn’t anything more they can do. I have reached out to WD Customer Support and exhausted all troubleshooting suggestions with them.