P2421DC, USB Type-C not charging

I have connected a Dell P2421DC monitor to a 2016 HP Elite x2 1012 G1 notebook via USB Type-C and it does not charge the battery. The laptop works well with a 45W and 60W external charger and the dock station in my office. The image display is correct with USB Type-C, but I chose this model precisely because of the possibility of charging the laptop with a cable.

I already sent an email to the support, but I not receiving any answer. I thinking to return the product.

I will appreciate if any of you can give some support.

Thank you in advance, Tomás.