So I followed directions in "Adding theme settings (advanced)" but for the life of me I can't find any page with theme settings. Is theme-settings.php still a thing?
If you are creating a custom theme then yes I think that file can still be created the same way as in D7. You could take a look at the Bartik theme in core.
I have had a read of what Lando provides, and it's an excellent development tool, and it would solve the problem.
But, I would prefer to find out why the problem is there in the first...
You might need to add a Relationship in the View to Flags. Or there might be a setting on the content type. I can't recall for certain but I think it's possible.
Comments
If you are creating a custom theme then yes I think that file can still be created the same way as in D7. You could take a look at the Bartik theme in core.