[SOLVED] Ubuntu14.04: D-Link DWA-171 no 5GHz network

Edit: Okay, so I have NO idea what happened, I didn't change a thing, but a minute after I posted this, the 5GHz network suddenly appeared in the networks list. I absolutely can use it now. This has become an embarassing first post now Sorry about that.

Original Post:
Hello everyone,

I caot access my 5GHz network at home for some reason with my dual-band D-Link DWA-171 USB-dongle.

I have installed the drivers for the dongle as explained in this thread by chili555. Everything worked fine, and I do have access to my wifi, but for some reason only to the 2.4GHz network, not to the 5GHz network (which is named YPNetworks5GHz for distinction). The 5GHz network doesn't even show up. I did install the dongle on Fedora 23 Linux (following the same instructions, and using the same driver) and on Windows before. In both cases it worked just fine with the 5GHz network, and my computer is still standing in the exact same spot.

I have attached the output of the wireless-info script of the forum to this post. As far as I can tell, the wlan1 adapter (which is the USB dongle) should work with 5GHz chaels, and it also found 1 AP (=access point, I guess?), but I couldn't find which one it is in the text. Maybe somebody can help me out here, it would be greatly appreciated. If I can assist by providing more information, I'm glad to comply. However, I will need explicit instructions, as I'm still very much a newbie at managing Linux.

Thanks in advance for all replies!

P.S.: And by the way, could anybody explain to me how to change my useame? I caot find that setting on the ubuntuONE site, and I'm not allowed to change my profile on this site because I do not have enough posts with "beans"?