Open BetterTouchTool at Login

I have set BetterTouchTool to launch when I log into my Mac. Or should I say I have set it up six or seven times to launch when I log into my Mac. The problem I'm having is every time I update the system software it disappears from the login items list. Other apps that I have set to open on login seem to be remembered but for some reason every time BetterTouchTool disappears from the list and I have to add it again. I'm assuming that as other apps remain in the list it's something to do with BetterTouchTool rather than Apple's system updates. Can anyone suggest anything to make it persist in the login items list?

You need to enable "Launch On Startup" in BTT itself:

Many thanks for that. I would never thought of looking there. For every other app I have it's just in the System Settings not in the app itself.