That's exactly what I'm using, pictured above. Sounds like it might just be a quality control issue, as mine is definitely not color neutral, and doesn't produce consistent results. I looked at product reviews on various sites, and pretty quickly found the same complaints I have. At least these complaints seem to be the exception and not the norm. The ones quoted below are from B&H.When shooting sports I always use a Lastolite LL1250 and like it. Works fine, but then it is a 12% gray card, not the older 18% that Ansel Adams so loved.
I suspect that you don't. I got mine years ago when Lastolite was putting them out with 12% gray on one side and white on the other. All their gray targets are now 18% gray.