Hasta La Motion!

I have been using Fusion 5 for quite some time now. Very recently I tried Fusion 6.1 and I did not need to set up DoF there until now. Today I tried the very frequently used technique of copying luminance (which they now seem to call lightness) of depth pass and copying it to Channel Boolean’s ZDepth channel. To my surprise, Fusion still kept saying it has no ZDepth. The original rendered depth pass is an EXR. So, under channel’s I set ZDepth to RED (later I also tried Green and Blue). When I try to see the ZDepth of that EXR, I see just pure white. But doing this on alpha works just fine. (I understand this would not be the correct representation, but I expected to see something definite, but there is nothing showing.)

Is there something I am doing wrong? Has something changed in Fusion 6?