kinesis "getShardIterator" gets stuck

I have a weird problem when fetching items from kinesis.

So when I have events in the stream, and Im querying for them with the correct timestamp, I get the result.

But if I don't have events in the stream or if I'm querying for times where not event are there The call getShardIterator gets stuck for several minutes.

That's why I added the "timeout" of 2 seconds.

Is there a better way to just get an empty response from kinesis if no events found?

Thanks

<?php

$getKinessisClient = new GetKinessisClient();
$kinesisClient = $getKinessisClient->get([
    
]);

$params = [
    'credentials' => array(
        'key' => 'xxxx',
        'secret' => 'xxxx',
    ),
    'region' => 'xxxx',
    'version' => 'latest',
    'http' => [
        'timeout' => 2
    ]
];

$kinesisClient = (new Sdk())->createKinesis($params);

// get all shard ids
$res = $kinesisClient->describeStream([ 'StreamName' => $streamName ]);
$shardIds = $res->search('StreamDescription.Shards[].ShardId');

$foundItems = [];
foreach ($shardIds as $shardId) {
    try {
        $getShardItParams = [
            'ShardId' => $shardId,
            'StreamName' => $streamName,
            'ShardIteratorType' => 'AT_TIMESTAMP',
            'Timestamp' => $from_timestamp, //PROBLEM HERE
        ];
        
        // this gets stuck (without timeout)
        $res = $kinesisClient->getShardIterator($getShardItParams);