No result with Query String dynamic Rest-PHP

When making the following request to a Rest API

$response = $this->client->request('GET',$this->urlReports, [
                 'headers' => $header,
                 'query' => ['messageId' => '1b15a714-ac04-4c48-bbc5-8b9a747e8d84'] 

I get back the information I need, but if I do it in a dynamic way

$response = $this->client->request('GET',$this->urlReports, [
                 'headers' => $header,
                 'query' => ['messageId' => $messageId] 

does not return anything to me as if I did not take the format or do not know, it is to clarify that $ messageId if it has the id that I need to see so that it is not empty, I have already verified it.

I am using the Guzzle 6 library for http requests