When using PXT-General with Live, if you switch to User Mode quickly after loading a set, you may not be able to switch back to Push's default functionality. This is not specific to PXT-General. I've reported this to Ableton, please do the same if possible. You can temporarily workaround this by waiting a few seconds after loading a set to select User Mode.
Also, upon switching back to Push's default functionality, the Push script does not re-initialize the Touch Strip or Aftertouch type. PXT-Live was able to workaround this, but that's not possible in the case of PXT-General. I've reported this to Ableton, please do the same if possible.