The work around your using to get to the talent tree is the best solution for that untill it’s fixed or until you get to level 70 as it only effects characters under 70.
Have not seen any reports about dungeon ques though. Do you have the appropriate ilvl for them?
Edit: looking at your screenshot, that’s how it usually shows if your gear isn’t good enough. When you hover your cursor over the greyed out options, what does it say in the tooltip?
Edit2: Apparently the talent bug has just this minute been hot fixed, so if you restart the game you might no longer need the work around.