When I’m using Tor and click the new identity button, the browser loads a new tab instead of the homepage I set. This issue has been going on for a few months now.
Yes, new identity is indeed different from a cold start to keep the tor process running.
Moreover, it clears also some non-PBM stuff.
The reason not to load a custom homepage is to prevent a low-risk information leak.
In the issue thorin linked, we’re preparing a way to warn about this possibility, but the idea is that once you accept it, you won’t be prompted again.