Your date of birth is missing. This information is needed to comply with the law.
I figure this happened because Google learned the true date, by other means.Anyone else seeing this?
The key to using a fake DOB is consistency. Use some simple formula to be able to reproduce your fake DOB on demand. If you can't do this, if you use different DOBs, Google will obviously know your date is fake.
As an example, here is what I do to create a consistent DOB for my fake online persona.
Swap month and day (instead of May 10th, I use Oct. 5th) then reverse the last 2 digits of year. My formula obviously won't work for you if the resulting date is invalid so develop your own. For example, you could subtract X from year, month and day. Or use your mother/wife's month and day with your year. Anything will work as long as you can remember and reproduce it.
My online persona also uses a different spelling variation of my name.
Once again, consistency is the key to not eventually being rejected or banned.