I just started a game in the Classical era as Arabia, and right away, the game started behaving oddly, like each random event happens twice on the same round, and lots of buildings have the same +x on resource icons more than once. I also started my first city on a hill and got something like +12 production from terrain, and got the normal production for the tile when I reloaded the map and started in a different spot. I also saw an Oasis with 6 gold in one place, and 3 gold in another even thought I hadn't built a bazaar. The one with 6 gold was near a city state, but still outside it's borders if that means anything.