Sorry for the lack of information.
Here is the complete info:
MacBook Air M1 base model
Autocad for Mac 2024.0.1
MacOS Ventura 13.4.1
Test both external monitors plugged and unplugged

Might be because of the 7 GPUs, But it is very weird because if I don't click on AutoCAD and try to pan the viewport, it is very very smooth. As soon as I click and pan, the frame rate drops again.