Acknowledged
CIQQA-4757

Venu 4 (18.30) restarts during Connect IQ app activities - anyone else?

Since the 18.30 update, my Venu 4 45mm restarts in the middle of any activity recorded by a Connect IQ app: black screen, Garmin logo, reboot, usually within 20 minutes. It happens with two different Connect IQ sauna apps. Garmin's own Cardio activity runs 20+ minutes without a problem, and my wife's vivoactive 5 runs the same app without restarting. It happens at room temperature with no notifications coming in.

After each restart the watch uploads a crash report to Garmin, and its error log shows an "RTL Trap" (error 0x028).

Is anyone else seeing restarts with Connect IQ activity apps on 18.30? 

4917049

  • Additional detail for CIQQA-4757.

    Environment

    - Venu 4 45mm, part number 006-B4643-00, software 18.30 (previously 17.39, without this problem).

    - My own Connect IQ watch app (ActivityRecording session, heart rate through Sensor, SDK 9.2.0). Also reproduced with another developer's published Connect IQ sauna app.

    Symptom

    While a Connect IQ app records an activity, the watch reboots: black screen, Garmin logo, restart. It happens at a random point, from a few seconds to 18 minutes in. No entry is written to CIQ_LOG.YAML.

    The watch's err_log records it as error_cause "RTL Trap", RTL Error Number 0x028. Example: 2026-10-3 7:25:52, programCounter 0x60f9c547, stackPointer 0x20064be0, uptime 1712437, pageStackDepth 4, pageStack 2498,2640,2499,2501, firmware Commit ID 314043690097d5e2fe8903ae36f59dc96ee2a625. Full JSON on request.

    The restart loses the whole recording: nothing is recovered, and nothing reaches Garmin Connect, not even the laps.

    Controls

    - Garmin's own Cardio activity on the same watch: 20+ minutes, no restart.

    - A vivoactive 5 running the same app: no restart in a 20-minute session.

    - Another developer's Connect IQ sauna app on the Venu 4: restarted at 15:04.

    - An independent customer of my app reports the same on a vivoactive 6, software 18.29: "every time it stops it locks my watch in the app and I'm forced to do a hard restart."

    Ruled out on the Venu 4: heat (room temperature, on the wrist, at a desk), notifications (none arrived), vibration on or off, developer FIT fields (it restarts with none requested), a fitContributions declaration (it restarts without one), background services (my app has none), redraw rate, ActivityMonitor polling and Storage access during the session.

    The watch has uploaded RAM dumps and logs to Garmin after the restarts. I can send the unit ID privately, the full err_log and test builds.