Here is the formula as Written:
=INDEX({Req Main Sort Summary}, MATCH($[LIBID]@row, {LIBID}, 0), MATCH([Script]$1, {Req Main Sort Header Row}, 0))
Here is what happens when I save it:
=INDEX({Req Main Sort Summary}, MATCH($LIBID@row, {LIBID}, 0), MATCH(Script$1, {Req Main Sort Header Row}, 0))
This is consistent, it will not hold the formula as written.