After looking for it and not finding any good answer (to my point of view), I wish to ask the community.
When all networks are available, my fairphone 2 is on 4G, all works fine. But sadly, when 4G or 3G are a bit less available (say 50% of the bar), it sticks back to Edge even if “4G preferred), 3G, 2G” is selected. I think a good workaround would be to add “3G only” and “4G only” into the menu. I know this can be done: I had it on a cyanogen rom on a galaxy ace.
Is there any easy tweak to get them available in that menu? With ##4636## I can choose what I want, but it’s not really what I could call user-friendly