SSL subdomain wordpress 404 error

I have installed wordpress site in main site www.domian.com and i have activate it SSL FREE Cloudflare.
It is working perfectly until i had it to install another wordpress site in subdomain store.domain.com.
I am having problem access it, main site is working properly but store.domain.com it is showing me 404 error.

I have tried following solutions but again i am having problem, can’t find any solution

Here is the .htaccess inside the folder /store:

#Send www to https
RewriteEngine On 
RewriteCond %{HTTP_HOST} ^www.store.mydomain.com$ [NC]
RewriteRule ^(.*)$ https://store.mydomain.com/$1 [R=301,L]

#Force Https
RewriteEngine On
RewriteCond %{HTTPS} !=on
RewriteRule ^ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]

# BEGIN WordPress
etc etc
# END WordPress

And inside the main domain folder public_html/mydomain:

  #.htaccess SSL
    RewriteEngine On
    RewriteCond %{HTTP_HOST} ^shop.mydomain.com$
    RewriteCond %{REQUEST_URI} !^/shop/
    RewriteCond %{REQUEST_FILENAME} !-f
    RewriteCond %{REQUEST_FILENAME} !-d
    RewriteRule ^(.*)$ /store/$1
    RewriteCond %{HTTP_HOST} ^store.mydomain.com$
    RewriteRule ^(/)?$ store/index.php [L]

    # BEGIN WordPress
    etc etc
    # END WordPress