When you change the title of a question, the URL changes, so it redirects to the correct URL. It's not any kind of error, Google Search Console just lists it for information. I doubt it's a reason for traffic loss.
However, Q2A currently does a 302 temporary redirect, perhaps it would be better to do 301 permanent. You could try it by adding this line:
header('HTTP/1.1 301 Moved Permanently');
before this line in pages/question.php