Maybe I missed a thread on this but my Mana reporting is bugged some times. It shows my opponents Mana count instead of mine it seems.
It's tricky because just before my turn I often double check what I had last turn and add 1 for my plans for the next turn. First couple times I noticed it this happened and I was short Mana for my plan. Then later I noticed it showed unspent Mana for me on my opponents turn when I spent it all my previous turn. Then I noticed it was tracking the same as my opponents Mana count in my counter on his turn.
Android phone. Only since the last update. During my turn it is always correct.