Bluetooth in Windows on MacBooks can cause stuttering for peripherals such as AirPods or mice. This might be able to be resolved by installing a particular driver version or checking other Low Energy devices connected to your Mac.

Other Low Energy devices

AirPods connect to your Mac using Bluetooth Low Energy, a technology introduced in Bluetooth 4.0, allows for simplified pairing and lower power consumption. Many peripherals use BLE, such as

• Microsoft Xbox One controller (Amazon aff)
• Various mice and keyboards, such as the Microsoft Surface Mouse (Amazon aff)

When more than one BLE device is connected to your Mac while in Windows, this causes all BLE devices to interfere with each other, causing lag and stuttering. This isn’t a problem in macOS, only Windows.

You can find out if a device is a regular Bluetooth peripheral or a Low Energy peripheral in Device Manager. View → Sort by connection, then open the Bluetooth enumerator and BLE devices are grouped separately to non-BLE devices.

Try disconnecting other BLE devices and trying again.

Updating drivers

Since this is only an issue in Windows, it must be a driver issue. The Bluetooth drivers that come with Boot Camp WindowsSupport are version 12.0.1.873. There's a better driver which Windows won't install automatically but should make available as an optional update in Windows Update at some point.

1. Go to Settings → Update & Security → Windows Update and click the Check for Updates button.
2. Open ‘Show optional updates’ for additional updates.
3. In the list should be an update for ‘Broadcom - System - 5/24/2018 12:00:00 AM - 12.0.1.874’, one minor version increment from 12.0.1.873.
4. Install this new driver, restarting when prompted (or manually after if not).
5. If the update is not in the list, you can manually download it from the Microsoft Update Catalog:
   https://www.catalog.update.microsoft.com/Search.aspx?q=Broadcom+-+Other+hardware+-+Broadcom+Serial+Bus+Driver+over+UART+Bus+Enumerator
   Make sure you select the right version, 12.0.1.874.

You can confirm the driver version and roll back after the update if necessary in Device Manager. Choose View → Devices by connection, then expand Microsoft ACPI-Compliant System → Pci Bus → Intel(R) Serial IO UART Host Controller → Broadcom Serial Bus Driver over UART Bus Enumerator.

This new driver doesn't fix all the issues for me, but it makes the stuttering massively better, going from multiple times a second to every couple of seconds.

Future drivers

Since AirPods and Bluetooth Low Energy devices work fine with the same hardware in macOS, it must be a driver issue in Windows. I hope this can be resolved with another update in the future, but with this last driver release being May 2018, I doubt it. It's a shame this won't be resolved properly through Boot Camp driver updates, but perhaps someone else has had more luck installing a different version of the drivers?