Hi Pio,
We have checked your given code example and we are able to reproduce the reported issue from our end.
We have confirmed the issue “While printing the Grid Add, Delete toolbar item get disabled” is a defect and logged a defect report. The fix for the issue will be included in our Volume 1, Service Pack 1 2018 which has been scheduled to be rolled in the end of March 2018.
Regards,Thavasianand S.