entire project lost touch input

I have a project which contains some buttons in a few canvases spread across a few scenes. I am not sure what happened, but suddenly none of the canvases accept touch input. Basically, if I put a button on the canvas, I can't touch it to click it. It does work with the mouse however. All of my scenes are experiencing this problem. I think that is probably a clue.

I have an EventSystem in each scene. Not more than one Event System. I can also create a new project and touch works in the new project. So it is something specific to this project. I am testing this with Unity Remote on my iPhone. I can click the buttons. It's just that touch won't work. Just to be safe, I have restarted my computer and iPhone as well. But again, touch works in other projects.

I'd be grateful for any insights. Thank you.

UPDATE FOR ADDITIONAL CLUES: 1.) If I zoom the camera way in, I can have my hit on an object detected. But only if I zoom all the way in to

1. If I have the moue pointer over a button in my unity scene, it turns a little grey as usual. Then if I use my finger to tap anywhere on the screen in unity remote, the button brightens. So the screen is detecting my touch. It's just not getting where it needs to.