Google-sheets – Google Sheets script not working if new script made for new sheet

Your task is better described as matching or lookup rather than filtering: you want at most one entry to be returned. This can be efficiently done with vlookup

=arrayformula(iferror(vlookup('SHEET 1'!A2:A, 'SHEET 2'A2:A, 1, False)))

This looks up every element of 'SHEET 1'!A2:A in the column 'SHEET 2'A2:A and returns what is found. The arrayformula part ensures that everything is handled at once.

You may still run into performance problems, in which case you should either get rid of any empty rows at the bottom of the sheet (they are being looked up, too) or to filter out the blanks. That is, replace:

• 'SHEET 1'!A2:A with filter('SHEET 1'!A2:A, len('SHEET 1'!A2:A))
• 'SHEET 2'!A2:A with filter('SHEET 2'!A2:A, len('SHEET 2'!A2:A))

I'll add some remarks on the script, although I haven't studied it much.

• Use getLastRow() instead of getMaxRows(), so that the loop runs only over the rows with data. Same for columns.
• Do not call setValue in a loop. Instead, store the values you want to insert in a suitable array output, and after the loop call setValues(output). You can see such an example here.

Unless I am missing something, on top of the getA1Notation error from the answer by @Rubén your onEdit function never calls NormalSort(). Change it to:

function onEdit(e) {
  if (e.range.getA1Notation() == 'D3') {
    NormalSort();
  }
}

For completeness, @Rubén stated in his answer that there is a "typo" in the OP's code. That we need to use getA1Notation and not getC3Notation, which is not a valid Google Apps Script property of the range class.

Also note that the OP's use of the eval could work provided the item avulauted is the full ine needed to call the function, or NormalSort(); which would probably entail adding "();" to the passed value.