I think that it is bad implemented the UI system, maybe you need to implement the Eventsystem inside your UI to make the buttons respond friend, something very similar was happend in my jam project. keep struggling to win.
Viewing post in Buddy's Bug Brawl jam comments
Well, I realize that if I only use keys I can play this game, I love the music of this game, is nice, but how to attack the ants, and how could rotate the camera. Well my feedback is the next: you could try to use the new input system to implement the use of control pads and joysicks, next, try to use the EventSystem inside your UI elements, it allows the use of mouse clics, third, could I attack the ants? you need a window which explain the mechanics of the game too. the game is great, you could work on it to enhance it. Good work.