Toolbar Icon transparency on WIndows 10

I use PNG Icons with a transparent background in my toolbar. Everything looks good on the Mac.
Under windows 10 the background of the icon is no longer transparent, but white.

I didn’t find any settings.
What can I do, another Icon format?

Thanks Andy

What version of Xojo and Windows are you using?

Give it a try with this image and see if you have the same problems as this works here for me here:

Hi Julian,

Thanks, but same problem with the ball…

What was the difference?

What version of Xojo are you using?
Can you reproduce the problem in a sample project?

Check build settings Supports Hi-DPI, I think yours is OFF.

Did a little test with Julian’s image and Hi-DPI OFF and it shows white background, changed that to ON and then is transparent. Running Windows 10 on Virtualbox.

Edit: it looks like a bug with normal images. I started a second test with Hi-DPI ON, then dragged the ball and created an imageset with only 1x image, changed Hi-DPI to OFF and the background was clear too

Thanks Alberto!
The switch was off. Now everything looks correct.