Mac Bluetooth Lag & Connection Issues After OS X Yosemite Update
Bluetooth bugs seem to be a recurring problem with Apple's latest software updates, as users running OS X Yosemite
say that the new Mac operating system has created connectivity problems with the Magic Mouse, Magic Trackpad, Apple wireless keyboard, and third-party wireless accessories and speakers.
In a growing thread on the Apple Support Communities forums, users report that Yosemite has created problems when connecting to wireless input accessories, including Apple's own hardware. Some have trouble connecting entirely, while others say noticeable lag has been introduced since updating to Yosemite.