Some sitelinks are missing for Q5084390.
at the time of writing https://www.wikidata.org/wiki/Special:EntityData/Q5084390.ttl?flavor=dump lists:
https://ar.wikipedia.org/wiki/%D8%B4%D8%A7%D8%B1%D9%84%D9%8A_%D8%A5%D9%83%D8%B3_%D8%B3%D9%8A_%D8%A5%D9%83%D8%B3 https://arz.wikipedia.org/wiki/%D8%B4%D8%A7%D8%B1%D9%84%D9%89_%D8%A7%D9%83%D8%B3_%D8%B3%D9%89_%D8%A7%D9%83%D8%B3 https://ast.wikipedia.org/wiki/Charli_XCX https://azb.wikipedia.org/wiki/%DA%86%D8%A7%D8%B1%D9%84%DB%8C_%D8%A7%DB%8C%DA%A9%D8%B3%E2%80%8C%D8%B3%DB%8C%D8%A7%DB%8C%DA%A9%D8%B3 https://az.wikipedia.org/wiki/%C3%87arli_XCX https://ca.wikipedia.org/wiki/Charli_XCX https://cs.wikipedia.org/wiki/Charli_XCX https://de.wikipedia.org/wiki/Charli_XCX https://el.wikipedia.org/wiki/Charli_XCX https://en.wikipedia.org/wiki/Charli_XCX https://es.wikipedia.org/wiki/Charli_XCX https://fa.wikipedia.org/wiki/%DA%86%D8%A7%D8%B1%D9%84%DB%8C_%D8%A7%DB%8C%DA%A9%D8%B3%E2%80%8C%D8%B3%DB%8C%E2%80%8C%D8%A7%DB%8C%DA%A9%D8%B3 https://fi.wikipedia.org/wiki/Charli_XCX https://fr.wikipedia.org/wiki/Charli_XCX https://ga.wikipedia.org/wiki/Charli_XCX https://gl.wikipedia.org/wiki/Charli_XCX https://he.wikipedia.org/wiki/%D7%A6%27%D7%90%D7%A8%D7%9C%D7%99_XCX https://hy.wikipedia.org/wiki/%D5%89%D5%A1%D6%80%D5%AC%D5%AB_%D4%B7%D6%84%D5%BD%D5%8D%D5%AB%D4%B7%D6%84%D5%BD https://id.wikipedia.org/wiki/Charli_XCX https://it.wikipedia.org/wiki/Charli_XCX https://ja.wikipedia.org/wiki/%E3%83%81%E3%83%A3%E3%83%BC%E3%83%AA%E3%83%BC%E3%83%BB%E3%82%A8%E3%83%83%E3%82%AF%E3%82%B9%E3%83%BB%E3%82%B7%E3%83%BC%E3%83%BB%E3%82%A8%E3%83%83%E3%82%AF%E3%82%B9 https://kk.wikipedia.org/wiki/%D0%A7%D0%B0%D1%80%D0%BB%D0%B8_XCX https://ko.wikipedia.org/wiki/%EC%B0%B0%EB%A6%AC_XCX https://lv.wikipedia.org/wiki/Charli_XCX https://nl.wikipedia.org/wiki/Charli_XCX https://pl.wikipedia.org/wiki/Charli_XCX https://pt.wikipedia.org/wiki/Charli_XCX https://ro.wikipedia.org/wiki/Charli_XCX https://ru.wikipedia.org/wiki/Charli_XCX https://sco.wikipedia.org/wiki/Charli_XCX https://sd.wikipedia.org/wiki/%DA%86%D8%A7%D8%B1%D9%84%D9%8A_%D8%A7%D9%8A%DA%AA%D8%B3%E2%80%8C%D8%B3%D9%8A_%D8%A7%D9%8A%DA%AA%D8%B3 https://simple.wikipedia.org/wiki/Charli_XCX https://sr.wikipedia.org/wiki/%D0%A7%D0%B0%D1%80%D0%BB%D0%B8_%D0%95%D0%BA%D1%81-%D0%A1%D0%B8-%D0%95%D0%BA%D1%81 https://sv.wikipedia.org/wiki/Charli_XCX https://th.wikipedia.org/wiki/%E0%B8%8A%E0%B8%B2%E0%B8%A3%E0%B9%8C%E0%B8%A5%E0%B8%B5_%E0%B9%80%E0%B8%AD%E0%B9%87%E0%B8%81%E0%B8%8B%E0%B9%8C%E0%B8%8B%E0%B8%B5%E0%B9%80%E0%B8%AD%E0%B9%87%E0%B8%81%E0%B8%8B%E0%B9%8C https://tr.wikipedia.org/wiki/Charli_XCX https://ur.wikipedia.org/wiki/%DA%86%D8%A7%D8%B1%D9%84%DB%8C_%D8%A7%DB%8C%DA%A9%D8%B3%E2%80%8C%D8%B3%DB%8C%E2%80%8C%D8%A7%DB%8C%DA%A9%D8%B3 https://vi.wikipedia.org/wiki/Charli_XCX https://zh.wikipedia.org/wiki/%E6%9F%A5%E8%8E%89%C2%B7XCX
but https://en.wikipedia.org/wiki/Charli_XCX and https://pt.wikipedia.org/wiki/Charli_XCX are missing from wdqs servers.
Sitelinks are supposed to be unique (barring T44325) so it's unclear what could have have happened.
If the problem mentioned in T44325 caused a duplicate entry for en and pt sitelinks then when deleting such item these triples might have been deleted from the store. Only a new edit on Q5084390 after the deletion would have been able to restore these sitelinks.