Grouped sprites with material or texture changes don't render correctly

Loose sprites:
[Link Removed]

When these three selected sprites are grouped, it stops rendering correctly:
[Link Removed]

Create or find two sprite assets
Place down two copies of sprite A and one copy of sprite B
Select the sprites in the order A B A
Click on the group button in the details panel

Expected: Nothing changes visually
Actual: All sprites after the first material or sprite type swap will be garbage (flickering on top of a previous sprite or missing entirely).