I have about 80% of the achievements done so far. I have been awarded achievements I didn't do, and not awarded ones that I have completed.

Some I got when I shouldn't:

-Row row your boat - Settle on new continent early...I got it for taking one step on turn one in a recent game.

-All the achievements for "win at X difficulty" I got in my first win on an easy difficulty

-Obtain 3 culture wonders through "conquest" - I got this just for building 3 of my own

-Obtain 3 "different" state religions in one game. I got by swapping to an enemy religion, back to my own, and back to that same enemy religion. So only 2 different ones, just multiple times

Ones I can't complete:

-As Mellories said the ones that count either 12 or 18 era stars get weird for me. I've gotten some to 18 in game before, but the tracker will stop around 10 or so

-Build every Wonder over multiple games. I've built them all, even made a checklist, but didn't complete

-Own 50% of all land in a win. didn't get but finished the task

-Nuke an allies capital. didn't get but did the task

-Lastly, Hire 5/10/20 armies. I got Hire 5 armies but Steam it just stopped adding up after that.

Those were the ones I recall being awarded incorrectly, or seem to have something wrong with them. Still though it's been fun achievement hunting and opening biases/traits for the persona.

I'm in the same boat as well, worth noting that I unlocked all the achievements below while keeping on playing after the end screens.

That doesn't feel quite right, since it basically means I could get almost all in-game Trophies and Steam Achievements after the end of one single playthrough.

Steam achievements unlocked after the end screens of my last playthrough :

Midas Touch

Amass more than 500k in money over several games.

Obsessive

Collect 100 Curiosities over several games.

Key Influencer

All Empire capitals are in your sphere of influence.

Nuclear Power

Possess 5 Nuclear Weapons.

Money, Money, Money

Produce at least 1000 Money per turn in a City.

Just Eat

Produce at least 500 Food per turn in a City.

Blasphemer

Destroy a Holy Site.

Don't Know Much About History

Destroy a Cultural Wonder.

Check my Bling!

Gain access to all Strategic and Luxury Resources available on the map by any means.

Capital Punishment

Nuke a capital.

I got the liege one too, but I am particularly sad about the Era stars on my last run. :(