This small UI bug is old (and maybe already reported), yet it was never fixed (DL and DA) :
1) the location of the cursor on the sliders (military, social and research) does not correspond to the percentage allowed, neither a) absolutely (cursor at the right end of the bar deos not correspond to 100%) nor relatively (I can have 42 on social and 56 on research ant yet the social cursor will be farther to the right)
2) when you increase or decrease the percentage of one slider, it does not evolve linearaly. For instance : I have 2 / 42 / 56 ; I want to increase my social production, but with one single click on the social bar right arrow I go to 2 / 81 / 17 ; with a second click I may go back to 2 / 43 / 55 ; with a third it may be 2 / 82 / 16 ; etc.
(If these points are not clear, I could post screenshots)

1a) is always the case ; 1b) and 2) do not occurr immediately (maybe it is only after one slider was locked, maybe it is on reloads, sorry for not testing), but once they're there they are a pain in the neck if you like to micro-manage your production each turn.
But I know Stardock is willing to fix bugs, so thank you !