In desktop mode terraria causes black bars around firefox

[0ype]

Your system information

• Steam client version: 1747772770 Mon, May 19 12:51 UTC -08:00
• SteamOS version: repair-image-3.7.7
• Opted into Steam client beta?: [Yes/No] No
• Opted into SteamOS beta?: [Yes/No] No
• Have you checked for updates in Settings > System?: [Yes/No] Yes

Please describe your issue in as much detail as possible:

In KDE-plasma, playing Terraria in fullscreen causes Firefox and Firefox based browsers to get black bars around them.

Steps for reproducing this issue:

1. Go to desktop
2. Open Firefox
3. Open Terraria
4. Alt Tab to Firefox

[zzag]

Some video games block compositing for better performance. Unfortunately, one side-effect of this is that some applications that utilize client-side decorations may have black bars like that. The issue can be worked around by forcing compositing:

Right click video game's titlebar and select "Configure Special Window Settings..."

then in the new dialog, click "add property..."

and add the "Block compositing" rule

click "Apply"

When SteamOS uses Wayland by default, this should work as expected out of the box.