When setting up an account via steam the date of birth field is verified according to the system's set date format.
I had a UK date format set on DD/MM/YYYY on my system.
The setup did not verify any date where the date in a month exceeded the 12th.
Example: 11/18/1990
I changed the system date format to the US date format MM/DD/YYYY and then the setup worked once restarting VR chat.