Soundcore puts out two tones every couple of minutes.
Anker Soundcore puts out two tones every couple of minutes. It does this if it is playing or if Alexa is shut off
It sounds like the battery may be low. Is it charging OK? Also, could you let us know which SoundCore speaker you are using from this list? https://www.anker.com/products/taxons/113/Audio
Echoing what @TechnicallyWell has mentioned, it does sound like a low battery. It might be worth charging with a different cable and wall adapter to rule out it not getting a full charge when connected.