Mixed issues not being reported

For the following config

<?xml version="1.0"?>
<psalm
    errorLevel="5"
    resolveFromConfigFile="true"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="https://getpsalm.org/schema/config"
    xsi:schemaLocation="https://getpsalm.org/schema/config vendor/vimeo/psalm/config.xsd"
    findUnusedBaselineEntry="false"
    findUnusedCode="false"
    usePhpDocPropertiesWithoutMagicCall="true"
    reportMixedIssues="true"
>
    <projectFiles>
        <directory name="src" />
        <ignoreFiles>
            <directory name="vendor" />
        </ignoreFiles>
    </projectFiles>
    <issueHandlers>
        <MixedArgument errorLevel="error" />
        <MixedAssignment errorLevel="error" />
        <MixedPropertyAssignment errorLevel="error" />
    </issueHandlers>
</psalm>

running psalm for this code

<?php

/**
 * Safely access the values in $this->params.
 *
 * @param string $name The name or dotted path to parameter.
 * @param mixed $default The default value if `$name` is not set. Default `null`.
 * @return mixed
 */
function getParam(string $name, $default = null)
{
    if ($name && $default) {} // suppress unused name warnings
    return null;
}

$type = getParam('type');
$type = strtolower($type);

echo $type;

I would expect the same errors to be reported as seen on https://psalm.dev/r/34a696dcc4

yet I get No errors found!.