Grouped Arches, Single color chase, is reversing the 3d

[JonB256]

Playing with a model of 6 arches. In preview, they display as 6 sequential arches.

On the sequencer timeline, I have a 40 second SingleStrand chase.
It is Grouped and going Right-Left. This all seems normal and the chase is sequential from arch 1 to arch 6

The odd part is that, when I click 3d Fade on, it looks GREAT until about the 20 second point.
From 0 to 20, I have a nice, bright head and a fading tail
From 21 to 40, it continues but now with a faded head and brighter tail (backwards fade)
It makes the switch when the 6th arch completes at around the 20 second point.

(this is in 4.0.29 - didn't try it until updating, so I don't know how it was in earlier version)

[JonB256]

Ok, it isn't just the 3d Fade. 

Normal (expected) chase action for an arch chase would be for it to be "like a water jet" appearing from the base, extending over the arch, then "fading" into the other end.

And, it does that for the first few repetitions. Then, it begins appearing "full size" and then fades into the other end. If you aren't looking closely, you won't notice the difference, but it is bugging me now.