Hello dear, I am telling you about my problem, recently I was working on push notifications for android devices (in my case a samsung a31 device with android 11) it turns out that when testing the notification the top icon of the notification is not seen with the image with a black background but upon further testing if seen with white background image.

both have a background, that is, they are not transparent and in PNG format, I cannot understand why this difference in behavior, I also mention that I am following the instructions to customize the application icon according to this link https://success.outsystems.com/documentation/11/delivering_mobile_apps/customize_your_mobile_app/modify_the_app_icon/#icons-json-template 

kind regards