Welcome to the community, @Kuzes!
I'm sorry to hear about your issues with the WD Red.
It sounds like this could be caused by a faulty connectivity to the HDD, so I'd recommend you try changing the SATA-to-USB cable and see if the drive will stay properly connected to the system. If you have access to another PC/laptop, you could also try plugging there. As soon as you gain access to the contents on the drive, back them up somewhere else immediately to avoid any potential data loss during the troubleshooting. It might also be a good idea to check if the HDD will stay connected if it's plugged internally via SATA to the mobo.
Checking its health and SMART status by running the QUICK and EXTENDED tests from
the Data LifeGuard Diagnostics for Windows is also advisable (after the backup).
Keep me posted. Hope this helps you!
SuperSoph_WD