Yes, it's frustrating for sure.Hi I am under ios 12.2 beta 4 and I can’t add anymore my google account to synchronize email calendar and contact. After the 2 factor authentification, it’s back to the accours election and can’t save it... very frustrating!!! Is it a known bug under the beta 4???
I don't believe it's a known bug for beta 4 (though check the wiki on the first page of this thread).
I also use Google accounts for email, calendar, etc, and I have no problem syncing them with my iPhone. I'm using 12.2 beta 4 on iPhone XS Max.
Not sure that helps, but in any case, good luck to you!