Did you edit starting credits?

I had the same problem (As Pentastar always era 6. I just had to restart the game completely and then start a new game.

Same problem for me :(

If the game is always pushing it to the highest era after you start then you've probably edited the starting credits in the files. The credit slider is the era selection slider, so if you raise those numbers the utility which checks the credits to change the era will always max out.