503 response when using `$plivo->lookup` before `$plivo->verifySessions`

[ambitionphp]

I received a 503 response from $plivo->verifySessions when using $plivo->lookup before $plivo->verifySessions. After debugging everything within my logic, I pulled in a colleague, and he discovered the issue.

$plivo = app(RestClient::class);
$plivo->client->setTimeout(40);

$response1 = $plivo->lookup->get('+15555555555');
...
$response2 = $plivo->verifySessions->create(
    '+15555555555',
    [
        'channel' => 'sms',
        'app_uuid' => 'xxxxx'
    ]
);

$response2 throws an exception, error message is an html 503 response

$plivo = app(RestClient::class);
$plivo->client->setTimeout(40);

$response1 = $plivo->lookup->get('+15555555555');
...
$plivo = app(RestClient::class);
$plivo->client->setTimeout(40);

$response2 = $plivo->verifySessions->create(
    '+15555555555',
    [
        'channel' => 'sms',
        'app_uuid' => 'xxxxx'
    ]
);

$response2 throws an exception, error message is an html 503 response

use Plivo\BaseClient;

$plivo = app(RestClient::class);
$plivo->client->setTimeout(40);

$response1 = $plivo->lookup->get('+15555555555');
...
BaseClient::$isLookupRequest = false;

$response2 = $plivo->verifySessions->create(
    '+15555555555',
    [
        'channel' => 'sms',
        'app_uuid' => 'xxxxx'
    ]
);

This works as expected.