Common UI Bound Actions and Action Bar on gamepad and Keyboard-mouse input

Seeing that removing and re-adding the IMC doesn’t solve the issue, from what I can tell in your setup you’re missing a Data Table, an InputData Blueprint, among other things, and need to enable some options in the Project Settings.
Here are some videos that explain very well how to properly configure the Common UI plugin so it works as intended.

I’m also sharing the official documentation, which covers the same setup steps I mentioned above and includes a section about CommonBoundActionBar that might be useful to you.

Common UI

Common UI Quickstart Guide

Common Bound Action Bar

Hope it helps! Let me know if you managed to fix it!