WebP uploads doesn't work properly anymore

Generally I’m using a version of Hey Dingus’ shortcut. I’ve explained it here. I guess that’s the API? But with the image above, I tested by manually uploading the WebP to the desktop site. (I never use the app.) Here’s a link to an image that got stripped of colour when uploading manually. (The reason I’m using WebP is that I want to reduce the size, but I don’t want to have to separate between JPEG and PNG. WebP is small for the amount of quality (also with photos), and also supports transparency. My shortcut has a Clop action to do the conversion.) Thanks!