I have an Audio Pro T10 bluetooth speaker. I use it to play music from my iphone. For some reason this morning, when I tried to use, I could not hear any music coming out. The iphone was connected and playing music. I tried my wife’s phone and this played perfectly. I finally realised that the music was coming through but really quietly at a really low volume.
It seems that you have reset your bluetooth connection. Go into bluetooth setting. Click the information button.
Then forget the device.
Then re-pair the phone with the bluetooth speaker. The sound should then work again. If it doesn’t then repeat the process.