How to fix the bug of spin animation in powerpoint 365

I found a bug in powerpoint 365. When I applied spin animation on any shape, the shape will have zigzag edge when spinning. So I removed the spin animation. Then I used morph transition and export the slides to gif file. But the shape still has zigzag edge when it starts spinning even in a gif file. How do I fix this issue? I am using the latest powerpoint 365.