Troubleshooting Mixpanel Session Recordings in GTM Setup

I have the "init" for record_sessions_percent with 100 as value in GTM. It fires always before the Main Mixpanel tag. But I dp not see recordings in Mixpanel. Only when i force a recording with typing mixpanel.start_session_recording() in Chrome console do I see a session recording checkpoint in the events tab of Mixpanel. What am I missing?