Hi oliver255,
Thank you for reaching out to Microsoft Community.
Just to confirm, your Bluetooth headset (paired and connected to your Surface Book 2) disconnects and wont reconnect automatically to the Surface after waking the Surface from sleep, right?
Please try these steps to troubleshoot the issue:
1: Run Surface Diagnostic Toolkit and check Windows Update
2: Update drivers and firmware
Check what is the current OS Build of your Windows version by going to Settings > System > About.
Go to Download driver and firmware for Surface, choose Surface Book 2 then click Download on the next page.
Choose the .msi file that matches your current OS Build and click Next.
After downloading, run and install the .msi then Restart.
3: Change settings in Device Manager
While the headset is paired/connected to your Surface Book 2, open Device Manager
Expand Human Interface Devices, double-click on Bluetooth Low Energy GATT compliant HID device
Select the Power Management tab
Uncheck option for Allow the computer to turn off this device to save power
Expand Bluetooth, double-click on Marvell AVASTAR Bluetooth Radio Adapter
Select the Power Management tab
Uncheck option for Allow the computer to turn off this device to save power
If this answer your question, we highly encourage you to inform our Community by clicking on Yes or marking my post as an answer. This will help other members who may have the same issue as you. Otherwise, don't hesitate to update us so we can further assist you.
Kind Regards,
Marrion Y.