Cpanel/SSL expert

Job ID: 34350780

Budget: £20 – £250 GBP

Cpanel, shared hosting
I have added-on a new domain websiteB.co.uk with a subdomain websiteB and files stored in public_html/websiteB.
My main site main.uk has an SSL certificate that covers the main site as well as all subdomains.
Typing websiteB.mainsite.uk into a browser produces a ‘secure lock’
Typing websiteB.co.uk into a browser produces an ‘unsecure lock’
I have tried .htaccess Redirect 301 / https://mainsite.uk/edu/index.html (edu is a subdomain covered by the SSL certificate) but that does not appear to be working or is working but on Safari it is reported as ‘too many redirects’
Related categories: PHP Linux Web Security HTML Web Hosting