As predicted, the drive is getting worse. Some remaps didn't even work (also indicated by the write error rate), others did, and there are still even more pending. RMA away!
For Advanced RMAs, WD often marks up the cost of the drive by 2-3x compared to retail. This is to protect them in the case they never receive the bad drive within 30 days. For example, a WD10EFRX (WD Red 1TB) warrants a potential charge of US$250, which is roughly 3x higher than the retail price. They only charge your credit card if they do not receive the bad drive.--
Making life hard for others since 1977.
I speak for myself and not my employer/affiliates of my employer.