Create new untitled file and open language mode quick pick

I have this macro

"macros": {"newScratchFile": ["workbench.action.files.newUntitledFile","workbench.action.editor.changeLanguageMode"    ]},

Which used to work great with this extension but it appears Microsoft broke it as some point in time.

Now when I activate it, I do get a new untitled file, and the language mode popup opens for a split second but then disappears before I get a chance to type anything.

Is there a way to fix my macro so the language picker remains open?