@MKPotts Thank you for the advice. I ran UTCT miler. 34hours on full navigation and with HR strap. Dimmed backlight to low and switched off all autolaps and notifications/tones/vibrations. Climb alerts were on. No SuuntoPlus guides. Still had 18% battery life left when I finished.

@Alessandro-Fasiello-0 very strange behavior, contact support and follow their instructions

@magbueno Great news! The 2.39.34 software update fixed my problem!

@michalpt said in S9 PEAK PRO - SuuntoPlus Guides not syncing: @zhang965 The new version 2.19.2 of the Suunto App for iOS was just released at AppStore, and everything works absolutely fine now! Hurrah! Fahrrad!