I purchased 2 TB Sandisk SSD's for an R710

Whilst they ran ok, we had a constant yellow warning on the front panel display "Disk error - Please review and clear" (for both drives). However everything looked fine in OMSA

About a year later - both drives fail at the same time. I RMA'd them, put the new drives in, and same problem - warning messages on the front, nothing in OMSA, but the server itself is running as normal.  

I don't believe we have been unlucky enough to purchase 4 SSD's at this stage, and as far as I can tell, SSD's are supported for the R710. I obviously don't want to damage 2 other SSD's.

What can we do to diagnose or remedy?