Why I cant connect to external display?

Hello,

I have this problem at my work with my MacBook Pro 2018.

While connecting to projector with 15m HDMI cable via USB-C hub I get no input on projector, but my Mac finds the projector and I can even change resolution of projector.

Then when I took a shorter cable my Mac suddenly started to mirror display. All windows laptops works perfectly with that projector and most Mac’s do as well.

Tried different USB-Chubs no help, and I had same problem with two different Projectors and two different MacBook Pro’s both the newer 2018 model.