ClearContents deleting data out of range - excel

Question

I am trying to have this piece of code clear the contents of a certain range, before I bring new data. This range has a header right in the above row, which is getting cleared as well, although the range doesn't include it.
I've tried specifying the range and having other cells selected before running it, but the header gets cleared anyway.
With MyResults
LastRowResults = Range("A16:K" & Rows.Count).End(xlUp).Row
.Range("A$16:$K$" & LastRowResults).Select
Selection.SpecialCells(xlCellTypeConstants, 23).Select
Selection.ClearContents
It's clearing row 15 and even the content of cell A9, some of the times I run it.
The goal is to have this range cleared, keeping formulas in some columns intact, so that filtered data down the road can be brought in, making up the report required.

Answer 1

Avoiding Select and Activate in VBA does miracles in performance and coding abilities (How to avoid using Select in Excel VBA). Concerning your code, try to avoid the header, if it is a default at line 16:
With MyResults
LastRowResults = .Range("A17:K" & Rows.Count).End(xlUp).Row
MsgBox LastRowResults 'Consider removing this line, once the code works.
Dim deleteArea As Range
Set deleteArea = .Range("A$17:$K$" & LastRowResults)
deleteArea.ClearContents
End With
In the OP code, there was a lack of . before the Range in this line:
LastRowResults = .Range("A17:K" & Rows.Count).End(xlUp).Row
Thus, the lastRowResults was getting its value from the ActiveSheet or the Sheet in which the code resides (if not in a module). The . is quite important in the With MyResult.
In general, when the last row is searched for multiple columns, then one should define exactly the expected output. E.g., the for the biggest last row, something like this is way better:
LastRowResults = .Columns("A:K").Find(What:="*", SearchDirection:=xlPrevious, SearchOrder:=xlByRows).Row