Puzzled - White values after capture profile applied

I use the ColorChecker SG as target for capture profile (BetterLight) using Pulse Color Elite software. If the same untagged ColorChecker target image is then loaded and the (new) profile applied and converted to my working space why does the white patch read, in Photoshop LAB, L=99 (or was it 100), A=-5, B=+2. I don't have the values right in front of me so this might not be exactly accurate. However, why are not A and B = 0? All white patches read same, and gray patches are all exactly 50. Do use Equalight though. This is enough to give whites a cast in my repro work I think. J Vee