Background on Dim Mode on my Samsung S2 transparancy issue

I’ve been trying to figure out this issue I have with my Samsung S2 & have had no luck. Im designing faces with a dim mode background in low transparancy. It shows beautifully online and app, but when I transfer to my watch, it goes black background. It will only show if I have it in 100% transparency. I am trying monochrome/black & white/grayscale, and none of that works on anything lower than 100% transparency. I’ve tried tinting the picture & it doesn’t work either. Im not sure if its just my watch that is not compatible for a transparancy lower than 100%. I wouldn’t mind it too much, if it wasn’t too bright for dim mode. Any help or suggestions? Am I doing something wrong? Any settings on my watch that I need to change?

TIA

Is it a half transparent png?

Im using jpeg. Do I have to use png?