I trust no HD test/fix program other than Spinrite by Gibson Research.
https://www.grc.com/sr/spinrite.htm
It reads every sector. If it has a problem or detects a weakness it moves the data to a spare sector that all HD have for the purpose. It then marks the original sector bad so it is not used again.
If there are too many bad sectors that end up using all the spares you are screwed. Personally, if it finds more than 20 I trash the drive. Especially if they appear to be in a close cluster.
You can try a warranty replacement but you will most likely get a refurb unit as a replacement.
Amazon has a NAS rated 3 TB drive for 122 USD.