This has been on a timer for 30 minutes after I've turned it in since I've been doing them for the past few days. Is this working as intended or should it be like all other exploration missions and start the timer when you pick up the first mission? Or, did I read that patch note incorrectly and only dailies start from when the mission is taken and not turned in?
Depends on which one you are referring to. There are two missions for b'tran cluster. The first is called "Chart B'Tran cluster" this one is a daily with a 24hr reset timer. The second is the standard "Explore B'Tran Cluster" which has been fixed, like the rest of the exploration missions, to have it's 30 mins cd timer start when you start the mission, as opposed to when you finish it.
After yesterdays patch, the timer for "Explore the B'Tran Cluster" still does not start for me until I after I turn in the first mission. All other exploration missions and the daily timers start when I take them.
I tested this by taking in excess of 30 minutes to complete the mission. It was not offered immediately upon turn in and I had to wait 30 minutes before the contact even showed in my list.