I can't change the camera scroll speed on the campaign map with m2ex

I've installed m2ex and it works great in every regard except the camera movement on the campaign map is set really slow and the slider doesn't change it. This is when I'm using WASD or the mouse. Middle mouse button panning works as expected though.

Its the same in vanilla and in ss6.4. I tried Setting it higher in preferences.cfg, turning off vsync and switching the camera mode to RTS classic but nothing worked. Can anyone help?