U2414H, Ubuntu 16.04, not detected using DP?

I am trying to use the DP on a Dell U2414H monitor but I don't get it to work. I read many issues on this forum about using the DP on this monitor and no solution did work. I noticed the setup was important for each solution so I'll try to describe it as accurate as possible:

• Two Dell U2414H monitors
• PC with Intel Core i7 7500U and Intel HD Graphics 620
• Ubuntu 16.04
• First U2414H connected with HDMI port
• Second monitor connected from DP (on pc) to mDP (on U2414H)

I've tried many things like rebooting or unplugging the power cable, but each time I connect the monitor with DP it goes directly into power save mode. According to Ubuntu, the DP is disconnected.

What should I try to get this working? Thanks in advance!