Happened to me once ; it just failed RMA it Kingston warranty for SSD is 5 years ,please check if your SSD is still covered.

Since it was in a USb 3 casing,have you updated its firmware?
https://www.kingston.com/en/support/technic...firmware-update

use Kingston SSD manager utility to check,upgrade SSD firmware based on your drive model no. . Before you send for RMA use it also to erase data securely.