Error 504, but the script ran. What could it be?

Question

Nginx

AJAX request I turn to the php script, it first runs for a long time and at the end of the script enters the data into the database. The data was entered into the database, but the page was still loading and displayed a 504 Gateway Timeout error. What could it be?

Answer 1

It could be 504 Gateway Timeout.
Increase the timeouts for executing the script on the hosting.

fastcgi_send_timeout 300;
fastcgi_read_timeout 300;