Why does my pattern brush have uneven gaps?

[Boldline]

I'm trying to create a pattern brush of a string of beads but I am getting these odd uneven gaps in the brush that I cannot figure out what to adjust to fix, much less know why they are like that to begin with. I turned on "rigid shapes" because it was otherwise warping the circles.

[VectorStyler]

@Boldline I will try to improve this, it can also be replicated here