Resolver IIIMalintha I am having exactly the same issue. I am using the 'old' slicer visual and not the 'new' one.
I have two pages with a synch slicer using the same slicer group name. When an item on the slicer is ticked, then the item is ticked on the slicer on the other page. All good.
However, when I untick that item (so there are no ticked items), then the item on the slicer on the page remains ticked.
It used to work fine in the past.
This is a relatively new bug introduced I think at least a couple of months ago, as my live version has the bug and it hasn't been updated since mid-April.
I am using version 2.130.930.0.
If I create a pair of synched slicers on a new report, it works fine.
If I create a new pair of synched slicers on an existing report, it works fine.
If I use a slicer from the existing report, copy it to a new page without synching, give it a new sync group name and then duplicate it to another page, then it doesn't work when clearing the slicer items.
This is consistent behaviour on other slicers in the same report.
This is a bug - can someone at Microsoft review? I have a big model working with 150+ customers and this has already been reported by our users as a bug.