I once had to debug a broken button on one of our internal systems, user helpfully sent a screenshot of the page in question so I'd know which button she meant.
I checked, and sure enough someone had broken it a few days earlier with a minor update. Took me maybe 90 seconds to apply the fix and deploy it, asked the user to try it now... still not working.
I asked her to close and restart her browser and try again, still not working. I dragged myself out of my chair and crossed the building to where she was seated to watch the continuing issue in person, she demonstrated clicking the button and noted that nothing was continuing to happen.
I pointed out that she was clicking on the screenshot she'd taken earlier and the actual button was behind it. Ticket resolved.