@benille You’d have to find the older firmware version. You could try to ask for a link and instructions in https://forum.suunto.com/topic/6836/firmware-collection

@Brad_Olwin That was when wearing a HR belt. It is interesting that if I go back to that run in Suunto App now, it no longer shows Lactate Threshold (or Anaerobic Threshold) for that run, but it now shows Aerobic threshold = 135, which in my opinion is too low. Today I’ve had another, pretty intense, run while wearing a HR belt and having ZoneSense enabled. This time it has detected Anaerobic Threshold of 150, which up from 145 it detected last time. That is still way too low. For almost the entire run, over an hour, my HR was in 152-158 range. That felt like an Z3-Z4 effort - clearly not above the anaerobic threshold the entire time, which I wouldn’t be able to sustain for longer than a few minutes. What is even messier is that in the Run details in Suunto App it shows Aerobic Threshold = 150, but there is no Anaerobic threshold: [image: 1751764017899-screenshot-2025-07-05-at-6.05.57-pm.png] But if I go into Aerobic Zones and Thresholds details it shows Measured Anaerobic Threshold = 150, but there is no Aerobic Threshold: [image: 1751764074448-screenshot-2025-07-05-at-6.06.42-pm.png] So clearly at least something isn’t right.

@Brendan-A.-MacWade not sure if steps reset with the watch turned off. Maybe the trigger for reset is the minute rolling over from 23:59 to 0:00. If this is not happening, maybe steps are not deleted. How about just not switching your watch off?

@marcomonari Did you remove HR zone duration in SuuntoPlus option in the watch before launching the activity ? This seems to solve synch issue on my side (iOS and watch firmware 2.43.12). But the older activities done with HR zone SuuntoPlus selected are still blocked (I deleted them to clean Sync Problem pop up in the IPhone App)

@ShinJCD said in Firmware 3.19.16: since 5 seconds are already more than enough Yep!

@Shlomo-Sackstein Hi, so did you do anything to the watch in the end? I have similar experience with my S9P recently. Basically at first it had the same symptoms as yours, 50%-60% then suddenly prompt for recharge. Then I tried to calibrate the charge calculation by discharging (painfully as it keeps shutting down under 50%) it to near 0% then recharging to full. The percentage during daily usage became more consistent from 99% to 10% however the actually battery capacity was still quite low, and was degrading quickly, maybe only 20% of the original capacity. The watch is being sent to support for checking. (More updates: Support replaced battery two days later)

@Dr1mo you can always try and see what they say

@larrybbaker I did as you told me watch reset, and still won’t connect…:( iPad and Suunto see each other via Bluetooth, but when I try to pair nothing happens

Bonjour a tous, J’utilise une Suunto 5 peak depuis 1 an, que j’ai connecté à mon capteur de FC (Polar H9). D’habitude tout va bien, à la fin d’une activité la montre charge 20 sec le temps de tout synchroniser et mon activité se télécharge sur mon application… Or depuis ce matin, en revenant d’une sortie vélo, ma montre reste bloqué sur l’écran “synchro données FC” avec le petit chargement… Cela fait 3h que rien n’a bougé… Je ne peux pas quitter cette synchro, j’ai essayé de déconnecter et reconnecter ma montre, d’enlever et remettre la pile de mon capteur de FC mais rien… Le seul moment où je n’ai plus cet écran c’est quand je reçois une notif qui s’affiche donc sur ma montre. Quelqu’un a t’il déjà eu ça, et/ou sait comment arrêter ça ? Merci ! Björn

Hi all! My Android mobile phone can connect and be paired with my Suunto 5, but it keeps on pairing once both devices are connected. Obviously, no performance data is automatically synced. The app and softwares are updated. What might be the problem? Thanks!

Interesting take! A lightweight Suunto with Stryd support would be a game-changer for runners. I doubt they’ll add it, but if they did, I’d consider it too. The T6c was legendary—2000 miles is impressive!