I bought a 256GB Samsung Evo Plus card and ran h2testw on it, with the following results:
The media is likely to be defective.
238.4 GByte OK (500042048 sectors)
1.8 MByte DATA LOST (3776 sectors)
Details:1.8 MByte overwritten (3776 sectors)
0 KByte slightly changed (< 8 bit/sector, 0 sectors)
0 KByte corrupted (0 sectors)
1.8 MByte aliased memory (3776 sectors)
First error at offset: 0x0000000004ff3c00
H2testw version 1.3
Reading speed: 82.5 MByte/s
It seems that some sectors are aliases for others causing data to be overwritten. I did encounter some issues when I was using this card, and I think this is why. Is this faulty card something I can send in under warranty? It hasn't even been a month since I started using it.