Detach loaded tab displays as new tab

[LaurenWags]

• Did you search for similar issues before submitting this one?
  Yes

• Describe the issue you encountered:
  When detaching a loaded tab, it displays as a new tab instead of the site you had loaded.

• Platform (Win7, 8, 10? macOS? Linux distro?):
  MacOS

• Brave Version (revision SHA):
  Brave | 0.18.20
  rev | 60bb9e6
  Muon | 4.3.9

• Steps to reproduce:

  1. Open a new tab and load a site (I used nytimes.com).
  2. Tear off/detach the tab.
  3. Detached tab is displaying the new tab page, not the site.
  4. Window the tab was torn from displays white page (known issue)

• Actual result:
  New tab is displayed instead of loaded site.

• Expected result:
  Loaded site should be displayed in torn off tab.

• Will the steps above reproduce in a fresh profile? If not what other info can be added?
  Yes

• Is this an issue in the currently released version?
  No

• Can this issue be consistently reproduced?
  Yes

• Extra QA steps:
  1.
  2.
  3.

• Screenshot if needed:
  

• Any related issues:

[bbondy]

Duplicate of #10376