NotSupportedError: GATT Error Unknown on connect

[chipimix]

Hi!
I've tried to connect nRF52 DK using web-device-cli demo.
After selecting the device upon clicking the Connect button I got the following error message:
NotSupportedError: GATT Error Unknown.
If I inspect the webpage using devTools I see this log:

I'm struggling with the reason why this error occurs! Perhaps its because the NUS has a high sample-rate?
Any help appreciated - Thanks!