Hello vallespir5,
Thank you four your queries.
1. If post missing the featured image, default image will appeared there. So, kindly check all the post have featured image or not.
2. Check all the options available on the widgets, you will have the options to make the widgets run.
3. Even if the widget options are not functional, kindly check by deactivate the activated plugins. It may due to the plugin conflicts well.
Let us know how it works or not.
Regards