"Replace with current URL" is bugged.

[rey]

the current behavior is actually expected. This is because the cache data in Incognito mode is isolated from that in normal mode. The bookmark management system attempts to look up the corresponding website icon in the browser's cache. Due to this isolation mechanism, the system can only search within the cache data from normal mode and cannot read the cache data from Incognito mode. Therefore, if you have never visited this URL in normal mode, it will consistently return an invalid icon.

This brings 2 questions:
1. Then why user is overall allowed to add bookmarks in incognito, if it's so isolated? = and those bookmarks are equally visible/usable in normal mode.
2. Why bookmarks added in incognito do have icons, no matter the isolation mechanism, and only lose them on "replace"?
There is definitely some pass that Add uses, but Replace doesn't.