Tempo Synch with Ableton DAW – Helix

Hi, I run my HX Stomp as an Interface with Ableton Live and the Tempo is synchronized to extern. When I change the Tempo in Ableton it also changes in the HX Stomp, but not perfectly. I build myself an endless delay, wich I can hold. And after a while it gets out of sync. This does not happen, when I dont sync with extern but put on the correct tempo manually in HX Edit, this way it stays in sync. But I´d like to not change the bpm by hand in every new song. Kind Regards, Philipp