I need to change the author slug from username to nickname:
This is what is set by default: http://domain.tld/author/(username)
This is what I need: http://domain.tld/author/(nickname)-(author-ID)
As I am running a multi-author-blog, I do need a functional fix instead of manually changing the author slug in the database. I tried the following workaround, but some authors are using special characters (e.g. "&", accent marks or umlauts) in their nickname, which is failing the solution.
Additionally, I need to get a solution for duplicate author nicenames. Maybe its possible to add the author ID to the end of the author slug?