MAME stutters when the layout is set to change resolution

[Elaphe666]

I have found a problem when I use ChangeResolution=1, for instance to stretch my 1920x1080 layout to a 2K screen. The problem is that all games in MAME perform really bad, never at 100% (my computer has more than enough power). However, if I run MaLa at the original resolution of the layout, MAME works perfectly. Any idea?

[Elaphe666]

I have tried in another computer, also with Windows 10. This computer's screen is 1920x1080. I have made a layout at a fixed size of 1280x720. When I run it using ChangeResolution=1 again all games run at around 80%. Actually, when I quit MaLa and the resolution of 1920x1080 is restored, the mouse pointer, the windows, everything moves slowly and stutters. I have to change the resolution from Windows control panel to go back to a normal performance. This is very weird. Anyway, a workaround in case I need to scale a layout to a higher resolution is to always set ChangeResolution=0 and automate the resolution change with nircmd before MaLa starts and restore it on exit.