This is very little to go on. You need try combine info you have.
Open for example a JPEG (a few actually) and do headers OK? If no, then yes you
could have block size OR offset issue. To get from cluster (from MFT runlist) to LBA we need block (cluster) size but also correct offset. What software are you using? Or do you mean sector size (0.5KB <> 4KB)?
In DMDE, select PH drive then select volume, toggle 'advanced' checkbox so you see bootsector > post screenshot
Example: