Wp not installed as https or ?

Hello all

I have a site where some of the images doesn’t show all the time. I was then made aware of https mixed content errors.

I wonder how this is possible, as my domain has had SSL from the beginning when i installed WP. And how is it possible looking in the database that all the links in there are only http – without the “s” ?

How is that even possible, as the guide to get things working is telling me to change these links from http to https ?

How can WP be installed on a domain with SSL and not save/set the links in the database to https ?

Or am i missing something ?

All the best
Carsten