Steps to reproduce the issue

Step 1: Create contact Category named "Writers" in administrator at back end. i.e., :: yoursite.com/administrator -> components ->contacts -> Categories

Step 2: Enable plugins "Content-Contact" & "User - Contact Creator" and choose category("Writers") to assign contact by default, Also enable "Automatically Publish the Contact" by clicking YES button. i.e., :: yoursite.com/administrator -> Extensions -> Plugins -> "Content-Contact" & "User - Contact Creator"

Step 3: Register your self with a new user name(John123) with different email ID(abc@xyg.com/any sample) from front end and get it activated. Or You can also Create a new joomla user as "Registered" from back-end user management.

Step 4: Go to Components->Contacts ->Contacts, there you can see the contact named "John123" which automatically created and connected to your registered email(abc@xyz.com)

Step 5: Go to administrator "Content->Article" to 'Create' or 'Edit' any one of the Articles(already created) from any desired category, and go to "Publishing" tab and "Created by" column, and link the contact(John123) as the creator of the article by clicking and selecting through user icon(blue in color). And then go to "Options" tab and make "Link Author" -> "YES" and then "SAVE"

Step 6: Go to front end to check the modified article and find the author(John123) linked contact form.

Expected result

Author name must be linked either without "Itemid" :
http://yoursite.com/component/contact/contact/John123
OR
http://yoursite.com/component/contact/contact/2-John123

OR

This is much better as below If possible;
http://yoursite.com/writers/John123
OR
http://yoursite.com/contacts/John123

Actual result

When clicked on author link, the contact from titled "John123" good enough, but the URL shows us as below: "http://yoursite.com/component/contact/contact/2-John123?Itemid=101"

Another Way:
Enable the "URL Routing->to "Modern" towards remove IDs from URLs, and click on the author link(John123) then it shows us an ERROR page of 404

System information (as much as possible)

Joomla! Version: 3.8.6 Stable
Server: Linux
Database Type: mysql
Database Version: 5.5.56-MariaDB
PHP Version: 7.1.16
Web Server: Apache
WebServer to PHP Interface: cgi-fcgi

Additional comments

Please help me by providing the best solution for the same ASAP If possible.
I love JOOMLA! Thank you in advance!

Regards
Meavin