Crashing Windows Bluetooth stack from ESP32?

[tpbedford]

Anybody crashing their Windows stack with heavy HFP and/or SPP use on their ESP32? That's what I'm seeing, but I'm struggling to isolate where the problem lies: In the ESP or in Windows.

There are very few Google results suggesting the Windows stack is susceptible to crashing, but that seems to be happening for me:

- My BT mouse stops working, and toggles between "connected" and "paired" in Windows BT settings. Powering off WIndows BT and back on again usually fixes this.
- My Bluetooth comports (from several devices) cannot be connected to from Windows, and sometimes disappear entirely from any enumeration of comports, requiring a reboot to restore.

It usually take 5-6 hours to crash, with SPP & HFP both continuously connected, and only mild traffic on SPP. So testing is very difficult if I can only run one test per night!

(We had abysmal performance with ESP-IDF 4.3 where it would crash within 10 minutes, and seemed to be related to interrupts. We discovered a fix to the btController binary lib in 4.4 fixed this, but the source code for this is not published so I've no idea what the fix was)