I want to edit a special cell, I use of selectCell and after

If you have some button outside the grid, the next can be actual for you.

Latest version of grid by default has next behaviour.
"any click outside of grid close current active editor"
When you clicking on any buttons - editor activated, but nearly
immidiatly closed because there was a click outside of grid.

To solve problem just block onclick event propaganation ouside grid, by
setting
    event.cancelBubble=true;
in you button.

If this doesn’t related to your situation - please provide any kind of sample where problem can be reconstructed.