New Input control UI - missfiring keyboard navigation event

I am trying to move by keyboard between buttons in UI. The event seems to be registered randomly.

I have to press down key 1-10x+ to move between two buttons in the menu. I would appreciate it if someone gave me a clue where to start debugging.

It seems like the input and the navigation event system is running in different update (dynamic, fixed) I checked the input system and it is set to dynamic update.

Navigation with the mouse works without problem.