After Update, the Change Date function after task multi-select does not work
On further inspection, it appears that the drop down is hidden when you are scrolled down your list. You have to scroll back up to the top after making all your selections to see the drop down list. It still appears that this is a new bug, so support question still stands. Thanks.
Thanks for the report. I have been able to reproduce this issue and have now passed it to the developers to fix.