Login options not showing on https://www.negativexp.com/

[ryanbr]

Description

With default shields, visiting https://www.negativexp.com/ won't show login option (via the login button)

Steps to Reproduce

1. Visit https://www.negativexp.com/
2. Click on Login / Signup
3. No social login icons show

Actual result:

Login options not showing

Expected result:

Reproduces how often:

With Shields enabled, Cross-site Cookies enabled will prevent this from showing

Brave version (brave://version info)

Version/Channel Information:

Version 1.5.115 Chromium: 80.0.3987.149 (Official Build) (64-bit)

• Can you reproduce this issue with the current release? Yes
• Can you reproduce this issue with the beta channel? Yes
• Can you reproduce this issue with the dev channel?
• Can you reproduce this issue with the nightly channel? Yes

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields? Yes
• Does the issue resolve itself when disabling Brave Rewards?
• Is the issue reproducible on the latest version of Chrome?

Miscellaneous Information:

Allow All Cookies is needed to show login/social icons.

[ryanbr]

Seems to still break if I allow individual cookies, (while still keeping cross-site cookies in Shields enabled)