z-depth ignored after time loop repeat

I have a basic animation (attached) where I have a red circle passing in front of a green circle, then the red circle returns but this time passes behind the green circle. I grouped these together and added a time loop to the top of the group. The circles take 2 seconds to complete their path, so I set the time loop duration to 2s and the duration of the canvas to 4 seconds.

On the first iteration of the animation, the circles behave as expected. On the repeat of the animation, the red circle always remains behind the green circle. It appears that once repeated, the z-depth is ignored.

Have I done something wrong or is this a bug?

NOTE: I’ve tried this with 1.0 RC4 and 1.0 RC5, same result.
zdepth-loop-test.sif (7 KB)

Looks like a bug to me.

A Bug report has now been filed