Diagnosis
The capacitive touch buttons have no physical travel or tactile feedback. Accidental activation is common, especially when handling the monitor or if it's placed near other objects.
How to Fix It
Develop a specific handling technique. Always pick up the monitor by the top and bottom bezels, avoiding the right-side edge where the buttons are located. When placing it in a bag, ensure the right side is not pressed against a book or charger. There is no software setting to disable or lock the buttons.
If That Didn't Work
The issue may be exacerbated by a screen protector or case that applies slight pressure to the bezel near the buttons. Remove any third-party accessories and see if the phantom presses stop.
Heads Up
The power button is also capacitive. A long press (about 5 seconds) is required to turn the monitor off. Brief accidental touches will not power it down, but they will wake it from sleep or open the OSD menu.