Precondition:
Have two password form entries that are considered duplicates from the point of view of the sort key [1].

Note: With the current password manager saving flow, this state should not be achievable, however there are cases in which such entries were saved in the past

What steps will reproduce the problem?
(1) Launch Chrome
(2) Go to Settings > Save Passwords
(3) Tap on the displayed password entry that you want to delete (duplicated). 
(4) Delete the form.

What is the expected result?
The entry and its duplicates were removed.

View returns to Save Passwords, the entry is no longer displayed because it has been removed. Re-entering the Save Passwords page won't display the entry anymore.

What happens instead?
The selected entry was removed, but its duplicates were not.

View returns to Save Passwords, the entry is no longer displayed, however when re-entering the Save Passwords page, a duplicate of the deleted entry is displayed.

[1] https://cs.chromium.org/chromium/src/components/password_manager/core/browser/password_list_sorter.h?rcl=44906581b49621ee2d7be6ef9a3f575db4dca331&l=25