Greetings @matty,
Could you describe how you’re executing your software here?
In addition to your application container I assume there is a Weston container of some kind running in parallel yes?
When you execute your application in your container are you executing it as the root or torizon user? By default xcb will have issues if you try to execute as the root user as described here: TorizonOS 6.5 Running a Qt app linked xcb under wayland
Best Regards,
Jeremias