Extra icon in taskbar/dock on Ubuntu (Gnome)

Hi
I'm experiencing an issue while using the application on Ubuntu (Gnome). When the application is running, an extra icon appears in the taskbar (dock). This icon is blank and has no associated window, as shown in the screenshot below:

When I open the application through the tray icon, the app window gets attached to this same taskbar icon. The icon then shows two windows: one with the actual app window and another one that remains blank, just like before. Here is a screenshot of the behavior:

I know that the screenshot doesn't give much details, so if you didn't understand the problem I'll take a photo on my phone and share it here.