This greatly effects me and I’m not sure if it’s just an issue on my end; I am unable to create posts without images which makes me unable to properly upload/display group logos, title cards etc.
I don’t see what’s wrong. Image’s transparent top is cut off (I can’t imagine why would anyone want that part to not be cut off), everything else isn’t transparent even in the original image.
It’s a problem with your image. If you look carefully, there’s an outline even in Explorer.
Discourse supports images with transparency just fine:
Maybe double-check if there is anything weird going on when you encode/save the image. It’s likely an issue on your end because it works fine for me and MrLonely1221 above.