Why are filters in an excel sheet showing unmatched rows?

Issue caused by blank (empty) cells at the column you are filtering. The actual problem occurred upon filter creation, while you made filter when you had first cell selected instead of whole column.

How to fix it:

  • Click at the first cell and press Filter again to delete current filter;
  • Then click at the first column and press Filter to create a new one.

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Now it will works like a charm. :)