I will attach some pictures to demo the issues.

This is poser 9 with a linear line going from 0 to.5 over the length of 30 frames. I added in a layer from 10 to 20 and placed a Key at 15. Notice that all 3 Keys are on the Red Line and that is at ZERO.

Now I moved the center of the Red Line up and notice the Black Line also moves up the same amount. Also notice the Keys at 10 and 20 remain at Zero.

This is the scene I made in Poser 9 imported into Poser 11.2. Notice the first 2 points are not on the ZERO line any more. Although they have Zero effect on the Black Line.

And here is the same scene with the center point being moved up. Notice instead of being separate as in Poser 9 they are on the same line. The biggest issue is that if Layer 1 is in add mode then you can not grab the center Key and drag it up or down. Below is what happens if you try to move the Red Line with the graph.

The Black jumps to some value and gets stuck. The Red line won't move at all. However you can move it with the dial or in the Poser window. And typing in a value.

Poser 5, 6, 7, 8, Poser Pro 9 (2012), 10 (2014), 11, 12, 13