Diagnosis
The monitor is powered on but receiving no video data. The most likely cause is an incompatible USB-C cable or port configuration.
How to Fix It
First, verify the cable. You must use a USB-C cable that supports DisplayPort Alt Mode and at least 60W PD. Check the input source on the monitor: press the joystick, navigate to Input Select, confirm it's set to USB-C. On your Mac, go to System Settings > Displays and check for detection.
If That Didn't Work
The issue may be a firmware or handshake problem. Power cycle the entire chain: turn off the monitor, unplug the USB-C cable from both ends, restart your Mac, then reconnect the cable and power on the monitor.
Heads Up
The PD2706U's USB-C port provides 90W power delivery. If your laptop requires more than 90W, it may charge slowly or not at all, but this should not affect the video signal.