@Remi_Laf I can't offer anything helpful other than to say I have one user of 10 that are all part of the same security group the dashboard / report is shared with experiancing this strange behavior. His slicer on one report page defaults to only show one user, and the only thing that works is to open the filter section on the right, select all users in the slicer and things on the report page pop back.
He's the only user like this, and I still haven't figured it out...
#3: It sounds like the known refresh issue, perhaps you can take a look at support:
We are experiencing a temporary issue where users who are using web.page function in their queries will not be able to refresh data sets. Engineers have identified the issue and are in the process of applying the fix. Next update by 08/31/2017 13:00 PST
>>For information I tried it with the ChicletSlicer and the HierarchySlicer and the native one.
I am having the same issue. I spent hours removing the chicklet slicer from all of my reports because it was broken.
Then I found out that it's doing the same thing for the Smart Filter by OKViz as well. So I do not believe it is an issue with the custom visuals, but rather a PowerBI online issue. It works fine on the desktop, but not after it is published.
The workaround is to search for a name in the Smart Filter, then click 'Refresh' at the top of the report.
Kind of embarassing though since I am doing training on this next week and have to teach the workaround in order for these reports to work correctly.