I came here looking for solutions as well. I use a little four channel mixer to combine recordings I'm listening to along with my bass. I plug headphones into the headphone jack, and this has worked well. I started using the G10 Relay for my bass, and it still works perfectly going into my mixer and out to my wired headphones.
I decided to go completely wireless and purchased one of those little BlueTooth transmitters to send from the headphone jack of the mixer to a pair of BlueTooth headphones. Instantly, the G10 has latency so bad it is impossible to play along with the recording. It's NOT the BlueTooth, because the music I'm playing is still coming through the mixer in real time - only the bass using the G10 is lagging, where it didn't lag at all when I was using my wired headphones.
Any clue what is causing this? I've re-seated the G10 transmitter in case it needs to choose a new frequency, etc., I made sure it was charged, etc.
Does BlueTooth somehow interfere with the frequencies used by the G10?
Thanks!