In a supporting document published today on its website, the company Apple Lossless Audio CODEC (ALAC), notified users that the Bluetooth functionality of Macs may be affected if devices USB 3.0 are placed in their vicinity. The keyboard and mouse connected via Bluetooth to the Mac could work sporadically, any other accessories could have similar functionality and all only if certain external USB 3.0 devices were near the Mac, Apple recommending users to move those devices to a distance appreciable by the computer.
Bluetooth enabled keyboards and mice may not pair or connect consistently, or audio from Bluetooth enabled earphones or speakers may be choppy. This can happen if certain external USB 3.0 devices are too close to your Mac.
Resolution
- Try moving external USB 3.0 devices further away from the computer, and away from your external Bluetooth devices. For example, if you think an external USB 3.0 hard drive may be causing an issue, try relocating the device away from your Mac or moving it to another side of your Mac.
- Make sure all USB cables are connected correctly. Better shielded USB 3.0 cables may also be helpful.
You can find the respective document here and I don't think you will find any other solution than the one previously explained.
