Move resetSplitShares below no-op guard in edit flow

Prevent no-op edits from wiping custom split shares by moving
resetSplitShares after the unchanged-amount early return. For
non-editing flows it still runs before navigation as before.

Co-authored-by: Eskalifer1 <Eskalifer1@users.noreply.github.com>

Author: MelvinBot

src/pages/iou/request/step/IOURequestStepAmount.tsx

@@ -397,12 +397,11 @@ function IOURequestStepAmount({
     const saveAmountAndCurrency = ({amount, paymentMethod}: AmountParams) => {
         const newAmount = convertToBackendAmount(Number.parseFloat(amount));
 
-        // Edits to the amount from the splits page should reset the split shares.
-        if (transaction?.splitShares) {
-            resetSplitShares(transaction, newAmount, selectedCurrency, !isEditing);
-        }
-
         if (!isEditing) {
+            // Edits to the amount from the splits page should reset the split shares.
+            if (transaction?.splitShares) {
+                resetSplitShares(transaction, newAmount, selectedCurrency, true);
+            }
             navigateToNextPage({amount, paymentMethod});
             return;
         }
@@ -414,6 +413,11 @@ function IOURequestStepAmount({
             return;
         }
 
+        // Edits to the amount from the splits page should reset the split shares (only when the amount actually changed).
+        if (transaction?.splitShares) {
+            resetSplitShares(transaction, newAmount, selectedCurrency, false);
+        }
+
         // If currency has changed, then we get the default tax rate based on currency, otherwise we use the current tax rate selected in transaction, if we have it.
         const transactionTaxCode = getTransactionDetails(currentTransaction)?.taxCode;
         const defaultTaxCode = getDefaultTaxCode(policy, currentTransaction, selectedCurrency) ?? '';