If you want to sync GP with Live in « follow tempo » mode, you will need to use the (older) MIDI clock message. In Live send the MIDI clock sync to a virtual MIDI port received by GP. It works perfectly.
At least the sync works perfectly. I am less satisfied from the « follow tempo » itself which is often twice the correct tempo. I tested several tracks with the same result. Perhaps, I missed something on the Ableton side… 