Looks to me like a driver issue, meaning the drivers that you made it on top of, and since then, have been updated and introduced some sort of anomaly into your masking.
Perhaps it's something in Blitz that always worked, and now doesnt due to driver changes by the manufacturer? DX vx Blitz would be my guess.
Perhaps it's something in Blitz that always worked, and now doesnt due to driver changes by the manufacturer? DX vx Blitz would be my guess.