I watched your video (+1 for making a thorough video!), and noticed some settings differences between the two characters.
There is also some wierdness going on, on your Horde I noticed you had a 0 - 0 connection, but were still seeing groups. This shouldn't be possible.
On your Alliance, I noticed you do not have "Auto join oQueue Channel" enabled. This needs to be enabled so that your toon will join the realm wide oQueue chat channel that the group information gets dumped into. When using this you also need to make sure you join at least one other chat channel like general, trade, etc. If You are not joined to a chat channel, oQueue will wait for you to join a channel before entering the oQueue channel. This is to prevent oQueue from accidently taking over /1.
On the bottom right hand corner you see your connection listed on your Alliance toon, you have a 0 -2 connection. That is almost non existant. Its best to have a 10 - 10 or better connection. Indicating you are connected to 10 Friends and 10 people on your realm. Joining oQueue channel and using the find mesh button are the ways to increase your connection.
I did notice you used the find mesh button, which is good. This will add people to your friends list to improve your connection. However I noticed you did not gain any friends when you pressed it on your Alliance toon. Due to Battle.net not really being designed to do the things we are using it for, the find mesh button doesn't always work unfortunately.
I also noticed that you are running a UI mod, maybe ElvUI or TukUI, I would recommend disabling all other addons while troubleshooting oQueue. ElvUI has a auto accept group invitations setting which is none to interfere with joining oQueue groups. So its possible there are other friend request related functions that could be interfering. Also, if any addons you are running interact with whispers, theres a high possibility they will interfere with oQueue.