Port https://github.com/ScratchAddons/ScratchAddons/pull/1139

src/addons/addons/block-switching.js

@@ -250,7 +250,6 @@ export default async function ({ addon, global, console, msg }) {
     blockSwitches["control_forever"] = [
       {
         opcode: "control_repeat_until",
-        remap: { SUBSTACK: "split" },
       },
       noopSwitch,
     ];
@@ -699,6 +698,12 @@ export default async function ({ addon, global, console, msg }) {
     workspace._blockswitchingInjected = true;
     workspace.getAllBlocks().forEach(injectCustomContextMenu);
     workspace.addChangeListener(changeListener);
+    const languageSelector = document.querySelector('[class^="language-selector_language-select"]');
+    if (languageSelector) {
+      languageSelector.addEventListener("change", () => {
+        setTimeout(inject);
+      });
+    }
   };
 
   const mutationObserver = new MutationObserver(mutationObserverCallback);