802.11ac (5Ghz) WiFi dongle on Pi3 can't connect to 5GHz SSID

I just received my new 802.11ac (5Ghz) WiFi dongle purchased from the OSMC store.
OSMC seems to successfully detect the dongle on boot, I can see both wlan0 (dongle) and wlan1 (pi integrated). Using the 2016.10-2 update of OSMC, the dongle appears to be reporting my 5GHz network’s SSID correctly but when I select it in MyOSMC Network I am not prompted for a network passphrase/password.
Must I disable the Pi3’s integrated wifi before using the dongle to connect?
I can certainly post system logs, but I wanted to ask if I am doing something wrong first.
Thanks!