Hi there,
I was having the same issue but finally managed to fix it. Are you testing it on a Xiami phone? It almost seems like the android phone is using some of the icons from ios resources. Although I’m not really sure about that.
I actually went through all .png files in the project folder and I found the sample icon in ios resources. So I regenerated the icons for ios (even though I have an android app) using ionic cordova resources ios, uninstalled the app in the phone and installed it again. And it worked!
I double checked all the .png files again and haven’t the sample icon anywhere.
Let me know if it helped!