Maximized windows cover the area behind the panel

Hello!

For some days I experience an issue with my top panel whenever I maximize the browser window (on a dual monitor setup). The window covers the area behind the panel as if the panel setting "Don't reserve space on borders" was checked. In fact I can workaround the issue by toggling the setting and the window is resized to the correct size.

I have no idea what caused the problem or if it's even rooted in XFCE.

Thanks for reading Sandro

xfce4-panel 4.16.3 (Xfce 4.16) Rolling release: https://github.com/archlinux/svntogit-packages/commits/packages/xfce4-panel/trunk