Playback Button Question

We are a small venue at a retirement community.  We're using a ColorSource 40.

Up until now we're only been using Playback Page 1.  We're trying more sophisticated things now, and want to use the other Playback pages.  I have found something that is limiting what I need/want to do.

This is a simple example:

1. Program Page 1 Playback Fader 1 to raise fixture 20.
2. Program Page 2 Playback Fader 1 to raise fixture 21.
3. Set both Playback Faders to level 0.
4. Raise Playback Fader on Page 1 to 100%;  fixture 20 is on.
5. Select Page 2.
6. Playback Fader 1 is up;  it is gray and the bump button is flashing dim white.  If I want to raise fixture 21, I have to move the Playback 1 fader all the way to zero, which lowers fixture 20 to zero.  Then when I raise Playback Fader 1 again fixture 21 goes up as expected.  This is not what I want to have happen.  I want to independently control these two fixtures.

I was not expecting there to be crossover between playback pages.  This is an unexpected limitation of the usefulness of having multiple pages.  Is there a configuration setting that I've missed?  Is there a bug in the software?

Thanks,

MIke