Facebook login

Hello,

our trial website - www.liveviber.com - has 4 login social buttons: Facebook, Google, Instagram and Twitter that worked regularly until today.
A couple of hours ago while I was doing some tests, I realized that the Facebook button does not work anymore. If I'm trying to login through this button a message does appear saying 'the email you entered is already in use....'' (See 1.jpg) while it is not. It was in use but the I erased it and cleared the cache but the message is still there.
The other 3 buttons work fine but the strange thing is the following:
If I login let's say through Google button and then I log out if then I try to login through Facebook (see 2.jpg) the system logs me as Google (see 3.jpg). The same happens with Instagram and Twitter. May you pleas ehelp me to understand what happened with Facebook Button and fix this issue?

Thanks

I am so sorry, I just found the issue. Some weeks ago I replaced my facebook email address with a different one which was included among EasySocial trial users and so the Facebook Button said me it was in use already. Now I erased it and the Facebook buttons works regularly.

Thank you anyway.

Regards,
Maurizio