Truncated Alert Sounds

Having a problem when using the Varia with Shokz open run headphones.

I only use the Shokz to get alerts from the Varia - I don’t listen to music.

When there hasn’t been traffic behind me for a while, the next alert I get will be truncated, that is, not as long as normal. Subsequent alerts sound fine, until there is another pause in traffic, then once again that first alert is truncated.

Almost sounds like a stutter, as if the Bluetooth connection is re-establishing, or one of the devices (phone or Varia) is waking up.

Shokz help desk says the open pro don’t ’go to sleep’ when there is no input, so not sure what’s going on.