PHP htmspecialchars returns empty string

here are various tests that show what does and doesn't work.  I cannot figure out what's wrong with the one that doesn't work.
The original text is much longer, but this is whittled down to a small test case.
(The original text is from a field in a db)

---
WORKS:
<?= htmlspecialchars("
                    <p><strong> Haven</strong>  at a very affordable  price</p>
                              ", ENT_QUOTES)?>
                             
                      RESULTS:    &lt;p&gt;&lt;strong&gt; Haven&lt;/strong&gt;  at a very affordable  price&lt;/p&gt;

---
DOESN'T WORK:   ("  satisfactory use.  "  was added in the string)
<?= htmlspecialchars("
                    <p><strong> Haven</strong>  at a very affordable  price  satisfactory use.  </p>
                              ", ENT_QUOTES)?>

                      RESULTS:       (blank)

---
DEBUG:
<?= strlen( htmlspecialchars("
                    <p><strong> Haven</strong>  at a very affordable  price  satisfactory use.  </p>
                              ", ENT_QUOTES))?>

                      RESULTS:       0

---

I also did a copy and paste back in the same place to "launder" the text thru notepad++  just in case there was a
stray special character, but no difference.

How to debug?    

thanks