Do you use Let's encrypt for that site? If yes, please follow this FAQ: https://www.howtoforge.com/community/threads/lets-encrypt-error-faq.74179/
are you even using ssl in your url? if you're typing http://<domain.tld> into your browser then there's no reason for it to show any ssl unless you're also explicitly redirecting http requests to https, even if the site has a valid certificate applied to it.
