home_url trouble

I am having the same issue as here:
and couldn't find a working answer.

While trying to activate Blacklist Monitoring or Website monitoring and a few other plugins I receive the following message:

It appears that your home_url setting is trying to redirect to another domain. This often happens when you are forcing https but haven't updated your site setting for that. Please verify that the home_url option of your WP install is correct, then click refresh updates in the Dashboard plugin.

In my Wordpress Multisite database it states correctly https://website.com, still I get this message. I also tried to define WP_HOME and WP_SITEURL in config.php, but it still fails.

What needs to be done. Thank you in advance!