Login form issue

Hello
There is something wrong with login form
For some reason it redirects me to external resources and duplicated my account
When I enter my email/pass after pressing login button it redirects me to FB for some reason asking me to login to FB
After I login to FB it redirects me to my OGS account
When I enter my username/pass after pressing login button it redirects me to Gmail asking me to login to Gmail
After I login to Gmail it redirects me to some new OGS account which is not mine.
Both accounts are assigned to the same email, I thought it’s not allowed…^^
Also I wonder why I’m redirected to FB/Gmail if I use my credentials, I shouldn’t be redirected in this case.

It redirects me to google credentials IF I fill my password incorrectly.
My account was originally created with Google credentials but after the patch I also added a password to my account.
I can log in with the password also but if I fill in wrong password it will redirect me to google credentials page.