After upgrading from 4.4.x to 4.5.x, the view of the activity stream has changed (for example unread). Previously there was a list of topics, but now a list of messages(posts). Users did not like this very much. Can this behavior be configured in the admin panel or through an add-on from the store?

Rebuild your search index to fix. Same thing happened to me. 

 

Thanks, it helped. I thought that every time the forum was updated, the indexes were rebuilt. Disabled Elastic, the list of unread messages was corrected. I started rebuilding the index on Elastic.