WiFi connection slows down significantly when Bluetooth headset connected (QCA9377 chip)

[Vasa Vasja]

STEPS TO REPRODUCE:
1. Connect laptop to internet via WiFi only.
2. Play any HD video on YouTube, etc.
3. Pair Bluetooth headset with laptop.

ACTUAL RESULT:
Video plays with long interruptions after Bluetooth headset was connected.

EXPECTED RESULT:
Video plays without interruptions when Bluetooth headset connected.

NOTES:
Bug reproduces on Ubuntu 18.04 and Ubuntu 19.10.

Laptop:
Lenovo IdeaPad 330-15IKB (81DE02VHRA).

Network chip:
QCA9377 https://www.qualcomm.com/products/qca9377

THERE ARE A LOT OF MENTIONS OVER INTERNET OF SAME PROBLEM OF THIS CHIP WITH UBUNTU BUT NO SUCH PROBLEM ON WINDOWS 10.
One of them:
https://forums.linuxmint.com/viewtopic.php?t=302482

POSSIBLE SOLUTION DESCRIBED HERE:
https://askubuntu.com/questions/1097230/ubuntu-18-04-poor-wi-fi-when-connected-with-bluetooth-headphone

Driver&HW info in attachment.

[Sebastien Bacher (seb128)]

thank you for your bug report, looks like a kernel issue rather than a n-m one

Could you add a 'journalctl -b 0' log from a session having the issue?

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1866628

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Vasa Vasja (vasa777)]

Attached log was recorded during performing steps from the description.

[Vasa Vasja (vasa777)]

@seb128 can you please set the Importance to move forward?