The easy answer: Tax is too high.
The lame answer: Idk.
The guess: Happiness modifiers weren't changed much if at all. I'm sure you know these but I'll list anyways: Tax rate, facility bonuses, development, raids, new conquest, shortages, and unhappy alien pop.
On a side note check your empire screen and run the numbers. You may be surprised to see you're collecting less than 70% anyways.
There are much smarter people on these forums than me and hopefully they'll give better advice.
Got it fixed, something was off in that game, so I just purged the game folder, did a steam reinstall, placed the mod and then the patch into Customization, and loaded saved game, and all things are now as expected. Just won my game.
Amazing mod! The extended tech tree really diversifies things!
< Message edited by rmse17 -- 8/18/2020 2:25:24 PM >