When trying to undo the insert_row action with trimRows enabled, not every row that was added is removed. I think the number of rows that do not get removed is equal to the number of rows that are trimmed. The behavior is only shown if you set the index position to be inserted to null though. I have created a jsfiddle to exhibits this behavior: http://jsfiddle.net/mountaineerfan5/L8mwwqqm/1/
I created a work around and used hot.countRows() as the index and the undo seems to work fine: http://jsfiddle.net/mountaineerfan5/L8mwwqqm/2/
Iām not sure why this occurs though.
Thanks