Setting framebuffer size is only available with DRM atomic API Raspberry pi 4

[getgo]

Hi,

I'm new to qt, but i trying to make some gui apps using qml. There's 2 events

first, before i change GPU allocation to 256 (before is 64) and resolution to 1280 x 1024 (followed by my monitor resolution), i use stackview example and it works ok except when i change font size of qtquickcontrol2 component like label and textfield from default 11 to others, in preview look expected but when i deployed, the text disappear and when i revert it back to 11 still disappear. I have to re drag the component at designer.

second, after i change resolution and gpu allocation, run and deploy

Setting framebuffer size is only available with DRM atomic API

show up twice, nothing happen but application still running. So is there something i missed?

i follow this tutorial link text. And module i installed is :

qtbase
qtsvg
qtdeclarative
qtquickcontrols
qtquickcontrols2
qtvirtualkeyboard
qtmultimedia
qtmqtt

Thanks