You should first make sure your QuNeo is on the correct preset. The Ableton controller script works with presets 9 and 10 (unless you have modified those presets). Please see the "How Do I Switch QuNeo Presets?" question for information on how to switch QuNeo presets.
You may also just need to reselect the control script in Live's MIDI Sync preferences. Try this:
- Open Ableton's preferences
- Go to the MIDI Sync tab
- Under Control Surfaces, select something other than QuNeo, then switch it back
- Under Input and Output, select something other than QUNEO, then switch it back
- Now see if it is behaving properly
- If it's still not working, try restarting Ableton Live