If widget button is selected and i press tab, it selects the next button :(

I have my inventory that opens/closes when i press tab, but when i click on one of the slots and press tab to exit the inventory, it isnt exiting, but selecting the next button. How can i prevent it?

It is due to the navigation functionality for widgets, which you can only de-activate by completely disabling keyboard focus support all together. You could either listen to the OnPreviewKeyDown event or close the menu from the controller instead (using an input event).

I cant find this OnPreviewKeyDown

You can override the function in any UMG widget. I.e. go to the graph of an umg widget and click override in the left panel.

Ok, i found it, but what i need to do in that function, here is a widget