I have a Magic Mouse connected to my new Macbook Pro 2019. The mouse is horribly lagging. I have another bluetooth device, a pair of Sony headphones, that is working horribly too.


  1. Both devices work perfectly with Macbook Pro 2018 in the very same location.
  2. I suspected interference with the Wifi(2.4 GHz) but when I turned it off the devices were still lagging
  3. Both devices are 100% charged
  4. The mouse's sensor is clean

I tried to reset PRAM and SMC, removed everything related to mouse from /Library/Preferences/, nothing helps.

BT signal strength on both Macbooks is the same: ~ -52 dBm.

I'd appreciate any help!

macOS version: Catalina 10.15.5

2 Answers 2


Interference in the 2.4 GHz range is very hard to measure and even harder to control.

Look to eliminate every single USB-C connection within 10 feet of either device to ensure you’re not generating the interference right next to the Bluetooth receiver on the Mac.

If your display connects via Thinderbolt 3 or USB-C this testing is not ideal but necessary. I have had one person add a USB Bluetooth low energy dongle at the end of a 6 foot (2m) type cable and tape / attach it to the wall next to where they sit so they escape interference close to the Mac. Most of the time, we use another radio frequency if the interference is coming from too close to eliminate.

Also, all sorts of electronics and motors can cause the interference, check everything in 30 foot range if you can’t get an actual tool to measure the RFI.

  • Thank you, @bmike for quick response. The laptop is not connected either to display or charger. I've disconnected all the USB-C devices from electricity but the issue still happens. Is there any chance that the new Macbook Pro has less stable bluetooth? I am asking because the old one actually works fine in the same location
    – fsquirrel
    Oct 3, 2020 at 14:53
  • You need to disconnect the USB from the Mac, that’s where the interference hurts the most. I have no new hardware to test in my lab, but yes - more people are having problems now that the prevalence of USB C grows and bad cheap adapters and cables are plenty and even solid vendors like Apple and Bellini can have well shielded parts that fail on occasion.
    – bmike
    Oct 3, 2020 at 15:00
  • 1
    There are no USB interfaces connected to the Mac... I wonder if there is a chance that neighbour's WiFi interferes with the bluetooth? I can check if my router's WiFi interferes with another WiFi but I am not sure regarding BT-WiFi.
    – fsquirrel
    Oct 3, 2020 at 15:23

I hace a Dell monitor to which I connect my MBP. When I disconnect the display I get no issues. Thanks for helping me get closer to a solution.

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