Diagnosis
The USB-C port is not delivering the expected 60W of power. This is typically a cable or source device compatibility issue, not a monitor hardware fault.
How to Fix It
First, verify the cable. You must use the cable included with the monitor or a certified USB-C 3.1 Gen2 cable that explicitly supports 100W Power Delivery. Check the laptop's power requirements. The 34WN80C-B port maxes out at 60W. If your laptop requires more, it will not charge.
If That Didn't Work
The monitor's USB-C Power Delivery negotiation may have locked up. Power cycle the monitor completely: unplug it from the wall outlet for 60 seconds. Reconnect and retry.
Heads Up
Some laptops, like certain Lenovo or Dell business models, use proprietary charging protocols. They may only charge from their own power adapter, even over USB-C. Check your laptop's manual for USB-C PD compatibility.