It looks powered to me, could the left piston have been blocking it?
Blocked pistons don't extend when the blockage is removed unless they get a block update (that is, if something changes in one of the 6 blocks right next to it).
So a piston trying to push a block of obsidian will extend if the obsidian is removed but it the redstone block was blocked by the left piston then the right piston won't update, so won't extend, if the left piston then retracts.
If that is the problem then you need to add a delay so one piston retracts (or at least starts to) before the other tries to extend.
I could be mistaken, it's not so easy to see the difference between redstone dust that is unpowered and dust with the lowest level of power.