diff --git a/artifacts/tx-os/src/pages/executive-meetings.tsx b/artifacts/tx-os/src/pages/executive-meetings.tsx
index 271c8574..fb897279 100644
--- a/artifacts/tx-os/src/pages/executive-meetings.tsx
+++ b/artifacts/tx-os/src/pages/executive-meetings.tsx
@@ -3412,8 +3412,10 @@ function ScheduleSection({
                 sortOrder: idx,
                 kind: a.kind ?? "person",
               })),
-              // #635: external meeting flag.
-              isExternal: editingMeeting.isExternal,
+              // #635/#639: external meeting flag — coerce to real
+              // boolean so an undefined state never silently drops
+              // the field from the PATCH body.
+              isExternal: Boolean(editingMeeting.isExternal),
             };
             try {
               await apiJson(
@@ -6691,9 +6693,12 @@ function ManageSection({
         // schedule survive a save through the Manage dialog.
         kind: a.kind ?? "person",
       })),
-      // #635: send the external flag so the server can force rowColor='red'
-      // and the cascade/postpone rules know to skip it.
-      isExternal: editing.isExternal,
+      // #635/#639: send the external flag as a real boolean so the
+      // server can force rowColor='red' and the cascade/postpone rules
+      // know to skip it. Coerce defensively — a stale render where
+      // state.isExternal is undefined would otherwise silently send
+      // `undefined` and the server PATCH would skip the column.
+      isExternal: Boolean(editing.isExternal),
     };
     try {
       if (editing.id == null) {
@@ -7571,21 +7576,26 @@ function MeetingFormDialog({
               onChange={(e) => update("meetingDate", e.target.value)}
             />
           </FormRow>
-          {/* #635: external-meeting toggle replaces the daily-number
-              input (numbering is now fully auto-assigned by the
-              server). When ON the row is force-tinted red and the
-              alert-postpone button is disabled. */}
+          {/* #635/#639: external-meeting toggle replaces the
+              daily-number input (numbering is now fully auto-assigned
+              by the server). When ON the row is force-tinted red and
+              the alert-postpone button is disabled.
+              `full` so it spans both grid columns on its own row —
+              prevents the toggle from sharing a row with the date
+              input and colliding with the time pickers below on
+              narrow screens. */}
           <FormRow
             label={t("executiveMeetings.manage.field.isExternal")}
             hint={t("executiveMeetings.manage.field.isExternalHint")}
+            full
           >
-            <div className="flex items-center gap-2 h-9">
+            <div className="flex items-center gap-3 py-1">
               <Switch
                 checked={state.isExternal}
                 onCheckedChange={(v) => update("isExternal", Boolean(v))}
                 data-testid="em-form-isExternal"
               />
-              <span className="text-xs text-gray-700">
+              <span className="text-sm text-gray-700">
                 {state.isExternal
                   ? t("executiveMeetings.manage.field.isExternalOn")
                   : t("executiveMeetings.manage.field.isExternalOff")}