The MPC Software's quantization feature is called "Time Correct" which snaps notes onto the grid based on the selected time division.
How to Activate/Deactivate Time Correct
Time correct is accessible on the toolbar above the grid. Clicking on "TC" will activate Time Correct or turn it off if it is already highlighted white.
If you do not see Time Correct (TC) on your tool bar. Please go to View > Toolbar > Show Time Correct to allow TC to be accessible on the tool bar.