A bug I have found is that I executed some SQL code inside PHPMyAdmin and left it for a while meaning that my session had timed out. I refreshed the page and I cannot be sure on the next steps as I have forgotten however I either logged in as normal or I simply didn't need to but I believe I logged in as normal after refreshing and it telling me to log back in. At this stage I received this fatal error:
Fatal error: Call to undefined function PMA_SQP_parse() in W:\xampp\phpMyAdmin\libraries\Util.class.php on line 1115
I assume it was trying to parse the SQL I already done. A refresh normally wouldn't cause that issue so I think it's related to the session being timed out.
I'm not sure if this is fixed on later versions.