ANONS, I NEED SOME HELP PLEASE

Whenever I save a badge as a png I can post here without any problems.

When I post it in Twitter DM, it is sometimes ok and at the moment it's ok.

When I post it in Twitter feeds it posts with a black background.

Same thing happens in Telegram.

I've done test after test and I can't figure it out.

Have attached an artwork that is typical of the problem.

Thanks for your attention.