Reactivity fix for the editableColumn and an update to the onChange behaviour for the formula value to ensure updates are detected

packages/builder/src/components/backend/DataTable/modals/CreateEditColumn.svelte

@@ -75,7 +75,8 @@
     editableColumn.constraints.presence = { allowEmpty: false }
   }
 
-  $: if (field && !savingColumn) {
+  const initialiseField = (field, savingColumn) => {
+    if (field && !savingColumn) {
       editableColumn = cloneDeep(field)
       originalName = editableColumn.name ? editableColumn.name + "" : null
       linkEditDisabled = originalName != null
@@ -84,6 +85,9 @@
         $tables.selected.primaryDisplay == null ||
         $tables.selected.primaryDisplay === editableColumn.name
     }
+  }
+
+  $: initialiseField(field, savingColumn)
 
   $: checkConstraints(editableColumn)
   $: required = !!editableColumn?.constraints?.presence || primaryDisplay
@@ -583,7 +587,12 @@
       title="Formula"
       label="Formula"
       value={editableColumn.formula}
-      on:change={e => (editableColumn.formula = e.detail)}
+      on:change={e => {
+        editableColumn = {
+          ...editableColumn,
+          formula: e.detail,
+        }
+      }}
       bindings={getBindings({ table })}
       allowJS
     />