can't login into https://www.skill-capped.com due to shields blocking cross-origin requests

[Programatic]

Description

I just updated to the new version and due to the CORS policy, I am unable to login to some websites. The main one was skill-capped.com.

Steps to Reproduce

1. Go to https://www.skill-capped.com/
2. Login
3. Nothing happens

Actual result:

This appears in the dev console:
Access to XMLHttpRequest at 'https://www.googleapis.com/identitytoolkit/v3/relyingparty/verifyCustomToken?key=AIzaSyAgHWuN2OEx5R827dHlKO9HsOuBwZ017n0' from origin 'https://www.skill-capped.com' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: Redirect is not allowed for a preflight request.

Expected result:

Continue to the login page

Reproduces how often:

Every time

Brave version (brave://version info)

Brave	0.57.18 Chromium: 71.0.3578.80 (Official Build) (64-bit)
Revision	2ac50e7249fbd55e6f517a28131605c9fb9fe897-refs/branch-heads/3578@{#860}
OS	Windows

Reproducible on current release:

Yes it does

Website problems only:

• Does the issue resolve itself when disabling Brave Shields?
  No
• Is the issue reproducible on the latest version of Chrome?
  No

Additional Information

Edit: I have contacted the site admins to get them to fix it if I understand CORS properly. I am just confused as to why it worked before the update and then stopped working after.

[man15h]

Yes, I'm facing the same issue. The website is working fine in chrome/firefox/safari and other browsers.

[man15h]

UPDATE: Issue fixes itself when Shield is disabled.

[iefremov]

Should be fixed together with #2252

[btlechowski]

Verification passed on

Brave	0.58.20 Chromium: 71.0.3578.98 (Official Build) (64-bit)
Revision	15234034d19b85dcd9a03b164ae89d04145d8368-refs/branch-heads/3578@{#897}
OS	Windows 7

I was able to login .

Verification PASSED on Mint 19.1 x64 VM using the following build:

Brave	0.58.20 Chromium: 71.0.3578.98 (Official Build) (64-bit)
Revision	15234034d19b85dcd9a03b164ae89d04145d8368-refs/branch-heads/3578@{#897}
OS	Linux

Verification PASSED on macOS 10.14.2 x64 using the following build:

Brave	0.58.20 Chromium: 71.0.3578.98 (Official Build) (64-bit)
Revision	15234034d19b85dcd9a03b164ae89d04145d8368-refs/branch-heads/3578@{#897}
OS	Mac OS X