Im trying to perform searchs on wikidata, but my query its a little weird. Some searchs are case-sensitive

EG: using "maradona" match perfectly but "cristiano ronaldo" don't. "Cristiano Ronaldo" match OK.

wikidata

SELECT DISTINCT ?item ?itemLabel (SAMPLE(?RIP) AS ?RIP) (SAMPLE(?image) AS ?image) WHERE {
  ?item wdt:P31 wd:Q5;
    ?label "cristiano ronaldo"@en.
  ?article schema:about ?item;
    schema:inLanguage "en".
  OPTIONAL { ?item wdt:P570 ?RIP. }
  OPTIONAL { ?item wdt:P18 ?image. }
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
  
}
GROUP BY ?item ?itemLabel

I expect to be able to search all with lowercase (or other way to handle it better)