I created a new user role based off Author and another user role based off of Editor. When the new Editor role looks at a list of posts, it can edit posts by all Authors but the posts of all new Authors are not links and thus not editable. The new Editor also cannot edit posts of other Editors or Admins, even though the edit others posts capability is checked. What’s the issue here?
I suppose that you did not set any additonal restrictions with URE Pro edit restrictions add-on for the editor role copy.
The most probable thing which may take place – some other plugin is involved here. Can you deactivate all plugins temporally and check if other post are editable for new editor role?
If Yes, then activate plugins back one by one and re-test to isolate a problem.