@pritamkr21
You have two instances of WordPress installed ?
I think you are going to 404 bc your site_home and/or your site_url is wrong.
https://help.dreamhost.com/hc/en-us/articles/214580498-How-do-I-change-the-WordPress-Site-URL-
Changing The Site URL
What is instance? My site is hosted on Google cloud hosting using bitnami wordpress.
You said :
“My main site is http://www.toolsnsoftware.com and also have a subdirectory”
What do you mean you have a sub-directory ?
You have WordPress installed at the root :
toolsnsoftware.com
do you have another installation of WordPress installed under /shop ?
Yes, I am installed 2 wordpress 1 in main directory and second in /shop directory.
@pritamkr21
If you take a look at your feed, you will see the shop/ directory in there under the <title> of your default post :
https://www.toolsnsoftware.com/feed/
Check your permalinks :
Settings –> Permalinks
and check the site_url and site_home values in your _options table :
Changing The Site URL
https://www.ostraining.com/blog/wordpress/site-url-and-home-url-wordpress/
Check your htaccess file :
htaccess
My site url and home url both are correct. Both have this url https://www.toolsnsoftware.com