Am a bit confused about your goals and your config, so could you help us understand?
As far as I can tell:
you have accidentally configured our DNS hosting, which is what is blocking the certificate for portal.lillaekonomibyran.se. You can disable this incorrect configuration here, and will need to before we can help: Netlify App (this operation will have no impact on your site’s service). After you do this, you can hit the “renew certificate” button here: Netlify App to get that certificate for just portal.lillaekonomibyran.se so you can use the new primary hostname.
this will also remove the “branch subdomains” config option from your site’s domain settings page (here: Netlify App), since that being configurable in our UI is only possible if you have our DNS hosting active.
then (after you let us know you’ve done that), I can add your new branch subdomain, which will be develop.portal.lillaekonomibyran.se, to the certificate.