It din work at first go to me also. Try multiple times by removing and inserting at the time laptop is ON and OFF and switch ON by keeping the cable plugged in. If still not working, try @Gavaudan solution switching the ends again with all variations. If not, then you can buy a new USB-C to USB-C. Also, beware in choosing the cable’s refresh rate as 60 Hz otherwise you’ll experience a lag in video. I found the cable which provided in monitor package has the 60 Hz rate capability.