I am also experiencing this issue. While in an army, the whole bottom right bar seems to be unable to be interacted with, I can't expand/collapse nor do most of the mouseover tooltips appear. The only tooltip that activates in an army is the budget one, but only if I hover the mouse over the coin icon to the left of the army panel.
If I collapse the army panel, I can get tooltips for the parties in the army to show up when I hover over the inf/health/party/food/morale but still not expand/collapse the lower right bar nor see the correct tooltips
Outside of an army all these things function correctly
I think what is happening is that the army panel is incorrectly layered to be on top of the lower right bar instead of beneath it thus it is covering the functionality of the rest of the bar