Grid Disabled
Symbol: 
If this command is available in the context menu of a focused class diagram or statechart, an element is positioned without a grid when changing its position. Snap to grid with grid space in the TwinCAT UML options (Extras > Options > PLC Environment > UML) is not ticked.
If you perform the command, the diagram will switch to Grid enabled. The option will be ticked.
See also: