Using clipman plugin on a panel with a background image that is tilled, does not render the background image under the icon

Distro: Arch

Desktop: Xfce 4.20

GTK Version: 3.24.52

When using a background image that does not cover the entire area of a panel but rather repeat itself (tilled), the background "break" under the Clipman icon.

In the following example I use a 27x27 image and as you can see there is a gap where you can see the desktop background image where the Clipman icon is located.

The issue does not occur when using an image that does not repeat itself and cover the entire panel area (27X1080) in may case.

(Same issue occurs with the xfce4-notifyd plugin)