Yesterday I saved and closed my UE. Today once I lounched it and decided to test game, UI doesn’t recgnise my clicks.
I checked blueprints, all buttons had their functions, buttons also have their hover and click states which didnt show up once I clicked on them in-game. (I see my UI correctly, just can’t interact with it)
Have you tried adding Print Strings to the OnClicked functions to see if any are firing?
Do you definitely have focus on the menu and have no other programs running which could be utilizing the mouse click over your game?
If nothing in the project has changed, try restarting your PC and see if the problem persists.
Print strings don’t show up both on screen and log. Only programs running are chrome and steelseries engine for headphones. They were running all the time I was using UE. I rebooted my pc, problem persists 
I also loaded another level (not menu) and controlls worked fine, mouse clicks were recognised aswell
SOLVED it :DD The problem was that UI background layer was in front of buttons (but they were still visible)