Whenever I post transparent AI generated png file for review it all rejected

You should post the original assets here for our review. Usually, the fault lays on the edges. The edges must be real smooth.

Please refrain from posting images with a checkered background without transparency as it will be confusing.
Customers will mistakenly think that the background is transparent and purchase the image.
If there is no transparency, use a solid background and post in JPEG format.

The two above that you submitted are not actually transparent. There's a checkerboard pattern, but this is actually comprised of pixels with a checkerboard design.