Linux with Valve Index: "clicks" do not work?

It seems that whatever is the main action of the game, it doesn't work on Linux with Valve Index. The hands appear on the menu, I can see the cursor and point the items, but if I click them, they don't register. I was able to start a game by using the mouse to select "new game", but then when I got to the section that I have to climb a ladder, that wasn't possible -- tried trigger, grip, everything to grab and climb it to no avail.