Archive Plus Filter Errors

When I enable Archive Plus I get this collapsible/expandable structure:

January 2020
February 2020
Post 3
Post 2
Post 1
January 2019
February 2019
March 2019
Post 1

If I click on any of the posts, that post alone is displayed - this is good.

If I click on any month or year the latest posts are displayed - it is not what the user would want. The user in this case would want to see all of the posts from the year or month clicked.

Have I implemented this incorrectly? or have I misunderstood the intention of the plugin?