On Fedora, the windows created by FunGraphics are not always or only partially printed. This bug appears like 9/10 times on Gnome.
The configuration I'm using:
Java JDK:
openjdk version "25.0.1" 2025-10-21
OpenJDK Runtime Environment (Red_Hat-25.0.1.0.8-3) (build 25.0.1+8)
OpenJDK 64-Bit Server VM (Red_Hat-25.0.1.0.8-3) (build 25.0.1+8, mixed mode, sharing)
The specs of my computer:

Sample code for reproduction:
val window = new FunGraphics(640, 400)
window.setColor(Color.RED)
window.drawFillRect(640 / 2 - 200, 0, 400, 400)