Rows below Sort & Filter range not showing after filter selections

[dwarnimont]

I have sort and filter applied to range A1:Z100. the SUM formula applied within the sort and filter data area is outside the sort and filter range in ROW 101. When i apply a filter selection criteria, row 101 is hidden. data much further below the the filter range does show. It's like my row 101 is somehow attached to the filter. Any idea what causes this?