When two rules have the same rule conditions used to display a banner and boost a category you can end up with conflicting rules and only one rule gets applied.
The best workaround here would be to combine these into one single rule that has one condition and multiple consequences. Keep in mind, to display a banner, you can't use the Visual Editor tool and you will need to use the Manual Editor instead.
To do this you could add a consequence as custom JSON Data with your banner, and then add an optional filter as a Query Parameter to promote the items you would like to promote: