You need to wrap your sumifs in a sum so like so (due to you using the array trick):

=IFERROR(
          SUM(SUMIFs($S$4:$S$5006,
                 $E$4:$E$5006,
                 "<"&'$A$1,
                  $G$4:$G$5006,
                  {"*C1*","*C2*","*C3*","*C4*","*C5*"},
                  $B$4:$B$5006,
                  $A$1,
                  !$P$4:$P$5006,
                  "South",
                  $C$4:$C$5006,
                  "=4",
                  $S$4:$S$5006,
                  ">0")
/$M14),
"-")

[See this link for an explanation][1]

I highly recommend you just use the Query function which is really made for this kind of situation. [1]: https://exceljet.net/formula/sumifs-with-multiple-criteria-and-or-logic

You need to wrap your sumifs in a sum so like so (due to you using the array trick):

=IFERROR(
          SUM(SUMIFs($S$4:$S$5006,
                 $E$4:$E$5006,
                 "<"&'$A$1,
                  $G$4:$G$5006,
                  {"*C1*","*C2*","*C3*","*C4*","*C5*"},
                  $B$4:$B$5006,
                  $A$1,
                  !$P$4:$P$5006,
                  "South",
                  $C$4:$C$5006,
                  "=4",
                  $S$4:$S$5006,
                  ">0")
/$M14),
"-")

See this link for an explanation

I highly recommend you just use the Query function which is really made for this kind of situation.