Javascript/lodash/React(native) Fix my Filterfunction

Im trying to filter my searchObject by using a keyword.

const searchObject = [{"id":"9508","t":"Saal"},{"id":"9507","t":"Ballsaal"},{"id":"9506","t":"Apfelwein"},{"id":"9505","t":"Holzapfel"},{"id":"9504","t":"Ball"},{"id":"9503","t":"Saaltreiben"}];

const handleSearch = keyword => {
if(term) {
var results= _.filter(searchObject,function(item){ return item.t.indexOf(keyword.toLowerCase()) >= 0 });
console.log(results);
} else {
console.log(searchObject);
}
};

The Original-Object stores 10.000 Items. This Object in this project is just an example.

I use my function for the keyword "saal" or "Saal". The function filters the Object and returns currently "Ballsaal" and "Saaltreiben" but not "Saal"... it should return "Saal", "Ballsaal" and "Saaltreiben".