Yes, UPT()->get_user_id() is returning the correct user id.

And, I added an else statement which is echoing whether filters/pagination are used.

I’m attaching two screenshots in case that helps.

Here is the relevant code:

<?php echo UPT()->get_user_id(); ?><br>

<?php if ( fep_current_user_can( 'send_new_message_to', UPT()->get_user_id() )) { ?>
<a class="text-link" href="<?php echo fep_query_url('newmessage', array('fep_to' => UPT()->get_user_id() ) ); ?>">Send Message</a>
<?php } else { ?>
This is an else statement test
<?php } ?>