In this case, selecting a slicer in Power BI might not work, and the following remedies are given for such cases.
Wrong Relationships: If your slicer isn't filtering properly, it's due to a field from a table that's not related to the other tables in your model. The first place to check is the Manage Relationships pane, ensuring proper setup.
Edit Interactions Settings: By default, the slicers affect all visuals of a page, but maybe they were modified. From the Format tab, select Edit Interactions, and check if the slicer is filtering out the relevant visuals.
Cross-filtering Issues: If your slicer field has a many-to-many or inactive relationship, it will not filter correctly. You might consider bidirectional filtering or activating the relationship using USERELATIONSHIP() in DAX.
Caching or Refresh Delay: Sometimes, the selections made in the slicer are reset due to the forthcoming data cache. You may try to trigger a manual refresh of your report or switch to using DirectQuery mode if working under live data.
Hidden Filters or Bookmarks: The app uses bookmarks or has hidden filters, which basically make the selections made in the slicer look inconsistent or false. In that case, check Filters Pane and Bookmarks Pane to see if any hidden logic is overriding the slicer selection.
