Subdomain multisite gives 404 on sub sites

I used a one click install to install wordpress and then converted it into a sub domain multisite. I have made the required changes to the wp-config and htaccess file.
The main site example.com works absolutely fine.
When I try to add another site, it shows that the site has been successfully added. But the address sub1.example.com shows a page that says no content here and sub1.example.com/wp-admin gives a 404 error.(These are both generic pages similar to what my server shows on any random subdomain)

I do have a wildcard subdomain registered but its corresponding folder on the server seems to have no wordpress related files.

What can I do to fix this?

Also, when I create sub1.example.com in wordpress, should I also register this subdomain on my cpanel or does the wildcard take care of it? And if I should register it, should I do this before creating a site in wordpress or after?
(I tried all 3 scenaorios but I still get the same problem)