Multiple posts on Author Archive, cannot assign new authors post-initial publish

I have same problem, some post show up 3 or 5 times in archive and admin interface when somebody try list specific author by name.

When turn off Co Author plus everything return to normal. https://minus.com/l5ZjNq9eijbJI – screenshot from admin.

Problem is in join function:
add_filter( 'posts_join', array( $this, 'posts_join_filter' ), 10, 2 );

https://pastebin.com/Lb89JP17 – there is my hotfix of that bug. I am not 100% sure if is correct but seems working

Wow, Ozzy! That did seem to fix the listing problem on the Archive page! Amazing! Thank you!

I haven’t yet tested whether it will solve the problem I am having with assignation of authors to posts, tho. It shouldn’t effect that, right? Any ideas on that one?

Oh, lordy, no! It looks like it fixed that, too! Good job, Ozzy! Hurrah!

Actually, it did not fix the author changing problem. I will open a different ticket for that, however.

@ozzyczech what specifically did you change?

In function post_join_filter() need to be INNER JOIN if $join is empty.

I am not sure if my changes are correct, there was no time explore all posibilities, but seems to be.

Still not working well @wpyoda: announce the same problem https://goo.gl/wWdj3

I think this is the proper fix for the author listing page.