UserAgent: Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.103 Safari/537.36

Example URL:
https://trakt.tv/auth/signin, https://github.com/login, http://pastebin.com/login.php, https://www.facebook.com/login.php, and many others including most Google sites.

Steps to reproduce the problem:
1. Navigate to the login page of a website such as those listed above.
2. Attempt to sign in.

What is the expected behavior?
You will be logged in correctly and redirected to the appropriate landing page with full access to your account.

What went wrong?
The login page just refreshes without signing you in. No errors are given (e.g. incorrect details, etc). The page looks identical to how it was before you tried signing in, and you have no access to your account.

Does it occur on multiple sites: Yes

Is it a problem with a plugin? N/A 

Did this work before? Yes I think it started back in February, but I'm not quite sure. It's been happening for quite some time now.

Does this work in other browsers? Yes 

Chrome version: 51.0.2704.103  Channel: n/a
OS Version: 6.3
Flash Version: Shockwave Flash 22.0 r0

These sites work fine in other browsers like Firefox. It's happening to more sites than the ones I listed, though those are the major examples I can think of right now. Interestingly, the log in process works perfectly in Chrome's Incognito mode and never fails, it's only in the standard Chrome session that log in fails like this. I have disabled all extensions, wiped all Cookies and Cache and restarted Chrome (and the computer), but the issue doesn't go away. It was occurring on Google websites too (e.g. Youtube, Inbox, GMail), however I managed to sign in to my Google account by appending ?noredirect=0 to the end of the Youtube sign-in page address and then signing in normally. Any help in resolving this issue would be greatly appreciated, since the inability to log in to the majority of my web accounts is a bit of a hindrance. Thanks!