I found that my scenario seems to be due to re-sizing my pages and the hidden slicer was outside of the new page dimensions (16:9). When I enabled view for the slicer to troubleshoot it I couldn't find it on the pages that it wasn't working on.
I did the following to resolve this issue:
1. Re-sized my pages back to previous larger format
2. Removed all of the slicers showing this issue (not syncing properly)
3. Re-sized my pages back to where I want them (16:9)
4. Added the slicer I need back and sync'd, hid it as needed.
Test, test, test!
Fixed and works as intended! (WHEW)
Amazingly after a year now this problem still exists. Rebuilding the pages and reconnecting/loading the data connections works until you change something in your report... then it all breaks again.
Thank you, thank you, thank you. This has been doing my head in for the last couple of days. I just couldn't understand or work out the sync slicers at all. As you say - I had a number of hidden slicers which I did not know about. Using the selection pane, I made them unhidden and deleted the ones I did not want. Everything works fine now. This needs to be addressed.
@cllawrence and I experienced something similar...in order to resolve our issues we turned on the edit interactions, have the Selection and Sync Slicers panes visible - then you select the "bad" slicer in the Sync Slicers pane, and turn the interaction to none for each visualization. We think that under File > Option/Settings > Options > Current File > Query Reduction and checking the box for Disabling cross highlighting/filtering by default will eliminate this problem from happening as you will need to turn on any interactions you need. It would be nice if the option was there to remove the "bad" slicer from the Sync Slicers pane.
I can only guess that we are syncing it incorrectly. In the page with the slicer which in my case is page 1, I ticked everything and only unticked the visibility part of page 2 and everything synced accordingly. If you hover your mouse to the first tick in page 1, it says add a copy of the slicer to the page and sync it. This means except this is ticked, the slicer will not be synced in other pages.
1. Choose View in the top menu
2. Choose to check Sync slicers and Selection Pane
3. Within the Selection Pane, unhide all slicers.
4. Move the slicers to the top within the Selection Pane and remove the slicers you don't need.
5. Refresh the page until your data is visible again.
Remember to check both Drillthrough filters and report, page and visualization filters.