I’ve got exactly the same problem happening with mine! Both adapters are charged, the lights turn on and they sync up….but no sound?! Did you find the Solution?
I got the same issues with the connection on between the transmitter and receiver, when I turn on they both pair n sync with the green light but after a few seconds of pairing like 5 or 6 seconds, they both again started to blink with the light and start searching for the connections, weird!