This is also happening to me. My saves from previous times playing are also nowhere to be found after installing the dlc and will crash as soon as I open the game or even fail to launch. If anyone can find a fix, plz let us know!

Similar here, I can't exit the character customize, I don't have a "finalize" button. Just forever stuck.

In the customization screen, on top there are different icons like 'hair', 'eyes', 'accessories' and stuff. And left to the far right 'arrow' icon button, there is a 'notepad with pen' icon.
There you can choose pronouns and gender and stuff. On bottom of that section you can find 'next page' with triangle icon.
Then from the next page, u can write your MC's name and stuff. And it also has 'next page' button. Then you can click 'arrow' button on the top row
to go to wirite MC's bios page, and find 'next' button near MC's portrait to finalize it.

My saves also are not saving. Is there a way to contact the developers?