Yes, I end up clicking on "Language -> AutoHotkey" and it fixes it temporarily. Thank you for confirming it is not just me who is having this problem.

I had been using userDefineLang_AHK.xml with Notepad++ for years but just a few weeks ago I started having a problems with it. I'm not sure what's the cause. After I install userDefineLang_AHK.xml, sometimes it works fine. But then other times usually after a few days some strange things start happe...