when in digital modes, you have digital delay settings to time align the satellites (all 5 speakers). when you switch to analog, you lose the delay, causing different arrival times of satellite/redirected bass sound.
this means that the out-of-phase adjustment will be different in every setup.
if someone were so inclined to move their sub to a position that's equidistant with the mains, use 80hz for digital HP and test for phase that way, it might verify that it ain't the crossover. you would not be testing the best bass, but rather the phase difference between digital and analog modes.
in other words, i suspect that this problem isn't unique to the 950. phase is time. very few people place their subs with time/distance in mind, and every setup is different in that respect.
just a view from the peanut gallery.