[6.x] Ensure sidebar tab is only active when sidebar area is hidden (#13501)

Author: duncanmcclean

resources/js/components/ui/Publish/Tabs.vue

@@ -59,6 +59,15 @@ function setActiveTabFromHash() {
     setActive(window.location.hash.substr(1));
 }
 
+watch(
+	() => shouldShowSidebar.value,
+	() => {
+		if (shouldShowSidebar.value && activeTab.value === 'sidebar') {
+			setActive(visibleMainTabs.value[0].handle);
+		}
+	}
+);
+
 watch(
     () => activeTab.value,
     (tab) => {