Issue with White Outline on Logos

Hi all, I’ve seen this posted before but am struggling to find the answer. On my images and wordmarks I’ll occasionally get slight white/light gray outlining that’s definitely not part of the image (it’s a clean PNG file of text coming straight from Photoshop). I believe I saw someone say uploading the image and reformatting it in another site worked, but cannot find that post. Any solutions? Thanks for any help!