Vsync adaptive half refresh rate

[sichars1968]

I always have this option enabled in the nVidia control panel because the sim runs so smooth.

Now all of a sudden the frame rate is not at 30 but between 45-60 fps and the micro stutters are back, although the option is still selected in the nVidia control panel. Anyone help me with why this is happening and  how to rectify it?

Thanks

Simon