[Desktop] incorrect reddit creator information displayed on panel

[LaurenWags]

Description

Incorrect reddit creator information can be displayed on the panel. It seems to happen when using back/forward navigation arrows between subreddits/posts and opening the panel although there could be other cases.

Steps to Reproduce

1. Clean profile, enable rewards (staging env)
2. Navigate to https://www.reddit.com/r/brave_browser/
3. Click on pinned post "Regarding Rewards Support (PLEASE READ)"
4. At the top where it says "Posted by u/Brave_Support" click on "u/Brave_Support"
5. When you're on https://www.reddit.com/user/Brave_Support/ open the panel, confirm you see "Brave_Support on Reddit"
6. Close panel.
7. Click back arrow 2x, you should be back to https://www.reddit.com/r/brave_browser/
8. Open panel.

Actual result:

panel should just say reddit.com, not Brave_Support on Reddit.

Page refresh fixes the above issue, however if you don't refresh the page and you open other posts on this page, they will all say "Brave_Support on Reddit", ex:

Expected result:

just reddit.com since afaik only users are supported for Rewards:

Reproduces how often:

100% with above steps

Brave version (brave://version info)

Brave	1.17.48 Chromium: 86.0.4240.111 (Official Build) dev (x86_64)
Revision	b8c36128a06ebad76af51591bfec980224db5522-refs/branch-heads/4240@{#1290}
OS	macOS Version 10.14.6 (Build 18G6032)

Version/Channel Information:

• Can you reproduce this issue with the current release? no, does not reproduce on 1.15.x
• Can you reproduce this issue with the beta channel? yes
• Can you reproduce this issue with the nightly channel? yes

Other Additional Information:

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

Miscellaneous Information:

cc @NejcZdovc @emerick

[LaurenWags]

Other STR:

Navigate to a sub reddit like https://www.reddit.com/r/AnimalsBeingJerks/
Note who the most recent post (at the top) is from, ex: opus1123:

Scroll down a bit and click on a post by someone else, ex: this one is from tyrannosau_ris:

Once the post loads, open the panel.
Was expecting tyrannosau_ris, but see opus1123:

Refreshing the page fixes this.

[LaurenWags]

+1 from #9136 (comment)