You can’t set the cycle markers from the marker list.
a simple right click or double click should do it but no. Also not in Cubase 7.5.
This should be part of intuitive design.
The case expained:
I needed to save a certain cycle for a while so I used the marker list to store the cycle. I was not using a marker track this time. I moved the cycle, and when I wanted to set the old cycle I just saved in the marker list, it turns out there’s no way to position the cycle from there! This can only be done from marker track.
I looked it up in the manual and was very surprised that this isn’t possible. This even qualifies as a bug.