As I understand, the count beside the user name is not displayed correctly in the Members page in the community site in SharePoint 2013.
1. The community site feature is in the site setting->manage site feature.
2. The Replies section will increase in value as replies come in fine, but once one is deleted it will not drop down. You could take a look at Sites property bag, it stores in three different parameters (Community_RepliesCount,
Community_MembersCount, and Community_TopicsCount). Following the steps below will walk you through getting to the property bag in SharePoint Designer 2013 and how to modify this value.
1. Open SharePoint Designer 2013, click Open Site and type in the URL to your Community site (if you have been here before you should see it listed in the Recent Sites section below this button)
2. Once the site loads, click the Site Options button in the ribbon (right most icon)
3. This will open the Site Options window and should be on the Parameters Tab, if not choose that tab.
4. Within the Parameters tab, you should see three items with a Name like "Community_RepliesCount" select this item.
5. with this highlighted/selected, click Modify.
6. This will open the Modify Name and Value window.
7. Place the cursor in the Value: text box and delete the number you see here and replace it with the correct number, click OK and then Apply > OK.
8. Now you can close SharePoint Designer 2013 and go to your Community site to see the updated value you just added.
You also could delete all three parameters (Community_RepliesCount, Community_MembersCount, and Community_TopicsCount) in SharePoint Designer 2013. Then when you delete the replies in the community site the number of replies will go
For more detailed information, you could refer to the article below.
The article below is about what's happening web part displays incorrect values in a Community site for SharePoint 2013.