Can’t save PHP $_POST code

Would you please cross check and let know that the issue persist only when the code contains $_POST, $_SESSION etc?

I could insert other basic PHP code like ‘echo’ and it saves fine but anything with $_ and it wouldn’t save it just goes to a 404 page.

Today the plugin is crashing WordPress so I had to deactivate it. I’m using WordPress 6 and PHP 8

I can reproduce this,

<form action=”<?php home_url( $wp->request ) ?>” method=”POST” class=”enter-activity”>
/// ya da yada ya da

<select id="userID" name="userID">
            <?php 
            if ($user_info->roles[0] == "administrator"){
                  foreach ($users as $user) {
                    echo "<option value='$user->id'>$user->display_name</option>";

/// ya da yada ya da

$newActivityID = isset($_POST[‘userID’]);

This is a pretty a simple coding job that’s not working, very dissapointing

WordPress 6.0.2
Insert PHP Code Snippet (V 1.3.3)