Clipboard works with onSelectionChange, when I click the same cell that will not copy the cell content.
try to click one cell twice, then ctrl+c, then ctrl+p in some text editor.
http://webix.com/snippet/f87fbf3b
I can confirm the issue, but not sure that we will be able to fix it.
Check the next snippet, it shows how the focus can be handled to allow the ctrl-c operations after multiple clicks, unfortunately it has a side effects, for example you will not be able to select text in the affected grid anymore.