PC has been perfect for a year, but now it restarts whenever I toggle my monitor power?

Hey everyone, I’m hitting a wall with a really strange issue and hoping someone has seen this before.

I’ve had my build for over a year now and it has been rock solid, no crashes, no overheating, nothing. However, over the last week, I’ve noticed a weird pattern: If I turn my monitor off and then back on while the PC is running, the entire computer immediately reboots.

The Details:

• It doesn’t happen every single time, but about 70% of the time.
• The PC doesn't "Shut Down" gracefully; it’s a hard reset as if I hit the reset button on the case.
• Once it reboots, everything works fine again until I mess with the monitor power.
• GPU: RTX 4070TI
• Monitor: MSI 185hz

What I’ve checked so far:

1. Cables: I’ve reseated the DisplayPort/HDMI cable on both ends.
2. Power: Both the PC and Monitor are plugged into the same [surge protector/wall outlet].
3. Drivers: GPU drivers are up to date.