Because they are using different android versions. Newer android versions I think from android 5.1 do not show icon by default. You have to do it manually.
But less than android 5 like 4.2.2 being used by the HTC can show icon.
Anrdoid 5+ = material theme. The icon isn't supposed to appear in the material theme.
Add to B4XPage_Created of B4XMainPage:
B4X:
#if B4A
Dim p As Phone
If p.SdkVersion >= 21 Then
Dim ActionBar As JavaObject = B4XPages.GetManager.ActionBar
ActionBar.RunMethod("setDisplayUseLogoEnabled", Array(True))
ActionBar.RunMethod("setDisplayShowHomeEnabled", Array(True))
Dim bd As BitmapDrawable
bd.Initialize(xui.LoadBitmapResize(File.DirAssets, "logo.png", 32dip, 32dip, True))
ActionBar.RunMethod("setLogo", Array(bd))
End If
#End If