Save and maintain indentation

In my PHP files I have lots of indentation. All of a sudden, relatively recently, I lose my indentation every time I save and re-open my PHP file.

I save a file with this sort of code:

echo('<div class="maintext">');
    echo('<h2>Cookies Info</h2>');
    echo('<div class="txt">Cookies explanation</div>');
    echo(<div class="txt">Further explanation</div>');
echo('</div>');

echo('<div class="maintext">');
    echo('<h2>Cookies Usage</h2>');
    echo('<ul>');
        echo('<li>Example one</li>');
        echo('<li>Example two</li>');
        echo('<li>Example three</li>');
    echo('</ul>');
echo('</div>');

I save my file and I open it again with PHPStorm and I have:

echo('<div class="maintext">');
echo('<h2>Cookies Info</h2>');
echo('<div class="txt">Cookies explanation</div>');
echo(<div class="txt">Further explanation</div>');
echo('</div>');

echo('<div class="maintext">');
echo('<h2>Cookies Usage</h2>');
echo('<ul>');
echo('<li>Example one</li>');
echo('<li>Example two</li>');
echo('<li>Example three</li>');
echo('</ul>');
echo('</div>');

I then go back and redo the indentation. But when I save and re-open my file most of the indentation is lost when I open the file. Most frustrating!

I have tabs set as 4 spaces.

Help!