My guess is, that it's epic speed with the new 1.5 Factor for the AI bonuses. This is huge and it feel like one step higher in difficulty. My expirience is the same: Playing progress on emperor and epic speed with a non religiuos nation makes it near impossible to get a religion anymore without a lot of luck. Fighting unhappiness is very hard. Progress needs a buff anyway.I'm using 4th UC but i don't think it's the cause for the massive yield inflation if that is truely the cause, i started a game on the previous beta using the exact same settings and mods on an objectively much slower and generally worse start than the matches i quit *dyes as forested plantation as opposed to pearls on the the match i quit* i managed to settle 7 cities and played the first 200 turns, my happiness did not drop below 70% without even completing the road connections between my cities.
Something feels really off in the current version at least for me .... Although i liked the changes in this version especially lighthouse and harbour CS but i think i'm sticking to the "playable" version for the time being.
Btw: Could anyone explain how the a/b/c bonuses work and where you can find the 1.5/3 factors for the gamespeed?