Suunto Vertical 2 – Bluetooth issues: connection loss after a few minutes and/or after stops”

[manno02]

Hardware
iPhone 17 Pro, 512 GB
iOS 26.4
Coros Dura GPS device
Heart rate devices
Suunto HR belt, purchased March 2026
Coros upper arm heart rate sensor
Polar upper arm heart rate sensor

Apps
MySuunto version 3.9.0
Coros app version V4.5.8

Watch
Vertical 2, purchased October 2026, SN 2543C6005743
Software version V2.53.42, installed 7 April 2026

Previous versions
2.50.28 same error as in the current version
2.50.26 same error as in the current version
2.48.16 no error regarding multi‑device management of HR devices

Error description
Since update 2.50.26 and in all subsequent updates, the use of multiple HR devices is no longer possible. The connection between the watch and the HR device drops after a few minutes, the value on the watch display either freezes or no value is shown anymore. This also happens when the correct sensor is selected in the options before starting the workout.

As soon as one or more HR sensors are connected to the watch and at the same time to an external GPS device (here Coros DURA), reliable measurement is no longer possible, the connection is lost, sometimes after pauses, sometimes after a few minutes without any apparent reason.

Even if only the Suunto HR belt is connected to the watch and the Coros Dura and all other HR sensors have been deleted, the watch loses contact with the belt, even though it was displayed correctly at the start.

The error is reproducible, but the trigger cannot be attributed to a specific duration or always to a stop. In most cases the disconnection occurs within a few minutes.

Screenshots of the last activity showing the error in the MySuunto app and on the Coros Dura are attached.

I tried to transmit the logs to Suunto on 8 April 2026 at 18:50 but it didn’t work until 1910, I will add this information.

[manno02]

[enneo]

Same here! I need to disconnect and reconnect the sensor in order to restore its functionality. I have only a single Suunto HR belt.

Hardware
Pixel 8a
Android 16

Suunto Smart HR belt

App version 6.7.12

Watch
Race
Software version v2.53.42, installed 7 April 2026

Previous versions
2.50.28 same error as in the current version
2.50.26 same error as in the current version
2.48.16 no dropouts

Logs sent at 19.28 CEST

Screenshot from yesterday: