Latest BetterTouchTool not working with Karabiner-Elements again

Hi! i'm setting up new macbook 16" 2019 with latest Catalina 10.15.5 (19F101)
i've noticed that once Karabiner Elements are turned on, my bettertouchtool shortcuts are not working.
BTT version: 3.389 (also tried alpha version with restart)
Karabiner Elements version: 12.9.0

affected input device: built-in keyboard only

when i kill Karabiner Elements - then BetterTouchTool starts working fine, i mean the following:
i've created combination Cmd+F12 to increase volume, so it increases volume when Karabiner Elements are turned off.

I'm a brand new user of Karabiner-Elements (long-time user of BTT) and I also find that after starting KE, BTT stops getting keystrokes. I also use the Rectangle app and it too stops receiving keystrokes after I start KE. Both start working again after stopping KE. Thus, it would seem to be a KE issue and so for now I'm just not starting KE (that's not a loss to me, as I never got as far as configuring KE to do anything for me!)

I'll probably will try to raise the issue with Karabiner at some point.

As for my system, I have a 2019 16" Mac with Catalina 10.15.7, BTT version 3.401, KE version 13.0.0, Rectangle version 0.30