Welcome, Cybertiiger!
Not sure how to find the RAID configuration. My NAS 2 has had 2 failed disc within the past 3 months, same port, so I have some doubts about the Synology NAs itself rather than the disc... It does not show that there is anything wrong this time..however when I access the files some come out with very strange looking names ICC7KZ-L (except the the dash is a wiggly one).
EDIT:
This seems very unfortunate!
I'd advise you to
backup all the data from the NAS somewhere else before proceeding with the troubleshooting. What is the RAID configuration of the NAS system where the WD Red is installed?
I'd suggest you to try troubleshooting the drive from your NAS system by using the incorporated SMART diagnostic tool from the manufacturer. There should be such a utility that would allow you to see the SMART attributes and health of the HDDs inside.
If you want to take the HDDs out of the NAS system, it could void their warranty and make the troubleshooting a bit complicated.
I'd advise you to consult with the NAS manufacturer's customer support for assistance, especially if they are still covered by the warranty.
Keep us posted with the results, though. Good luck!
SuperSoph_WD