Yes.
I have, unfortunately, seen this multiple times. The display is dying. The pads on the USB-C connector are starting to separate. The issue is intermittent (and very odd) at first, but eventually it won't turn on at all anymore. It's usually better after the display has been powered off for a while. As the connector goes through thermal cycles the issues gets worse and worse. The only solution is to try and have someone repair it by desoldering and resoldering the connector. It is a delicate operation and the odds of it working are about 50/50. I have had two fail like this and neither were recoverable. This video actually explains the issue:
All Ultrafine 5Ks will fail in this way given enough use and enough time. Some earlier than others. The best way I've found to extend life is NEVER let the display charge a device. Always power your device separately. Powering the device over USB-C causes excessive heat on the connector. USB-PD should really be disabled on these displays all together.