DIAGNOSIS That's usually the monitor's built-in power-saving feature kicking in aggressively, thinking there's no signal when there actually is. It's a handshake issue, not a hardware fault.
FIX First, try turning off the power-saving modes. Press the joystick button on the back of the monitor to bring up the menu. Navigate to General > Energy Saving and set it to Off. Also, go to Picture > Screen Off and set that to Off. This often solves the random blackouts.
IF THAT DIDN'T WORK The problem might be your HDMI or DisplayPort cable. A low-quality or damaged cable can cause intermittent signal drops. Swap it out for a certified high-speed cable, preferably the one that came with the monitor, and see if the issue stops.
HEADS UP If you're using an adapter (like USB-C to HDMI), that's a common weak point. Try connecting directly from your computer's video output to the monitor's port without an adapter if you can.