ST claiming active device is offline

I have an ST3 and it has an Aeotec Range Extender 6 z-wave device that’s extending z-wave to an ecolink contact sensor.

This has been working fine for weeks, but suddenly the ST app insists the contact sensor is offline. Strangely the contact sensor is talking to the hub just fine and is triggering a notification automation whenever it is opened or closed. The device history shows all the activity events, but the ST app still insists it is offline. Z-wave repair doesn’t resolve the misleading status.

I excluded and re-added the device and it seems back to normal. However, clearly there is some bad state possible where devices are working fine but ST reports them as offline.