Checking around the community, this issue has popped up from time to time. The main cultrip seems to be the way Photoshop and similar software save PNG data information in its channel. There’s one thread with a pretty clear solution for this, please check it out:
don’t paint ui elements on a white canvas. you gotta use the “border color” of your elements. so only the alpha controls the shape. it should not be present in the color channels.
