regular expression does not seem to work well

[rpf5573]

class-editor.php - function pre_get() : 250

anspress use this code
$this->value = preg_replace_callback( '/<img\s+src="([^"]+)"[^>]+>/i', [ $this, 'image_process' ], $value );

This regular expression does not seem to work.
I'm not good at regular expression, and that code did work 2weeks ago...but my test show that it doesn't work.

Here is my test.

Check please!