Cesar,

Now that you're able to get an error msg I strongly suggest to look on google : https://encrypted.google.com/search?hl=en&q=Failed to pair%3A org.bluez.Error.AuthenticationFailed

You're problem might be linked to a driver bug, but i doubt is linked to ubuntu touch itself, even ubuntu.
Good luck

Hi Mario,

I will test the nexus build this week. I have a number of miracast dongles.

Does bluetooth work on the nexus 5 now?