Fetching BLOB via PDO odbc is missing parts of the result

Description

We're trying to stream an image from our IBM i filesystem (IFS) by fetching a blob via PDO. However the result is missing half the blob in a repeating pattern.

The following code:

$db = new PDO("odbc:DSN=NAME", 'user', 'pass');
$stmt = $db->prepare("SELECT * FROM TABLE(QSYS2.IFS_READ_BINARY('/path/to/file.jpg'))");
$stmt->execute();
$stmt->bindColumn(1, $type, PDO::PARAM_STR, 256);
$stmt->bindColumn(2, $lob, PDO::PARAM_LOB);
$stmt->fetch(PDO::FETCH_BOUND);

Resulted in this output:

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

But I expected this output instead:

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

Comparing the two results below, we see the missing parts highlighted in blue:

We do get the right result using the same driver and query in different languages/ applications so it seems to be a problem in php odbc or PDO.
It also doesn't matter what file we try to stream.

PHP Version

PHP 8.1.5

Operating System

No response

Start by reproducing the shown PDO ODBC query with PDO::bindColumn(PDO::PARAM_LOB) and PDO::fetch(PDO::FETCH_BOUND) on PHP 8.1.5, then inspect the PDO ODBC BLOB-fetch path. Done means the complete BLOB is returned without the repeating missing sections seen in the report.