Slicer and table show duplicate options

Hi Echoy51 

This happens if those columns are custom sorted mutliple times  (Value A with sort value of 1 and 2) which the GUI doesn't allow but can be enforced using Tabular Editor. But this doesn't seem to be the case for you  so the only plausible reason is there are invisible characters before or after in either of those seemingly duplicate values. You can confirm this by removing duplicates in sorting them in the query editor. You can try as Ritaf1983 suggested. If that doesn't work because the characters cannot be removed by using either Trim or Clean, I would right click one of those cells, click replace and that should show the special character if ther are any.

In the screenshot below the invisible character denoted by #(8208) which is possibly a line break. You can leave just this character and replace it with nothing.