If you set the QA_DEBUG_PERFORMANCE constant to true in qa-config.php, you will see a detailed description below each page of how Q2A spent its time in handling that page. That can be very helpful for finding out the problem.
Welcome to the Q&A site for Question2Answer.
If you have a question about Q2A, please ask here, in English.
To report a bug, please create a new issue on Github or ask a question here with the bug tag.
If you just want to try Q2A, please use the demo site.