Error activating Blacklist in Defender

When I try to activate Blacklist in Defender, I get the following error:

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.

I recently enabled SSL on my primary domain. When I go to https://mydomain.tld/wp-admin/network/site-info.php?id=1, it shows HTTP. When I go to https://mydomain.tld/wp-admin/network/site-settings.php?id=1 (and everywhere in my database since I did a search/replace), it shows HTTPS.

I've enabled support access.