New identity fails to block loading a custom home page

Noticed in the 15.0 release candidate build.

Steps to reproduce:

1. Set home page to https://example.org.
2. Trigger new identity.

Result: I get a new window with the https://example.org page already loaded. I still get the "Tor Browser blocked your homepage (example.org) from loading ..." notification though, it just doesn't reflect the reality.