From whence %E2%80%8E at the end of post link

Mystic! I don’t know why, but if I use code like this:

<?php
    $original_permalink = get_the_permalink($original_post_id);
?>

<a href="https://wordpress.stackexchange.com/questions/238467/<?=$original_permalink?>‎"><?=RU_LINK?></a>

I get %E2%80%8E at the end of URL.

But if i use different names of variables my code works fine:

<?php
    $ru_link = get_the_permalink($original_post_id);
?>
<a href="https://wordpress.stackexchange.com/questions/238467/<?=$ru_link?>"><?=RU_LINK?></a>