Custom icons losing detail

I have a 32x32 PNG image that I want to use as a custom icon. From what I understand, the icons used are 32x32, so there should be no loss in resolution/detail when importing. As you can see from the screen captures, the original image has lost detail when it was imported with Scrivener’s High DPI Mode enabled, but Scrivener’s built-in icons are still rather detailed. When Scrivener’s DPI mode is disabled, the icons are so small I can’t really see anything very well. If you’re not familiar with XnViewMP, the “100” in the status bar indicates the image is being displayed at 100% (i.e., no scaling).

If it makes any difference, I am using a 4k display with Windows scaling at 150%. The icon looks the same whether or not I set the Override-High-DPI scaling parameter on the executable’s compatibility properties. Same results when I move Scrivener to my second monitor (that’s not a 4k display), which is doing Windows scaling at 125%.

Scrivener’s High DPI mode enabled:

Scrivener’s High DPI mode disabled: