I’m in the same position: bought the B28 system to get rid of the cables about 18 months ago and indeed, the pairing works sometimes fine for a week, then it’s deteriorating and the secondary speaker doesn’t follow. Full reinstallation didn’t help. Wifi strength is fine. I wonder if there’s anybody happy with the wireless solution. Conclusion: I will cable the primary speaker to the router and the secondary speaker with a cat 6 cable.