504 error on post requests?

Question

PHP

Good evening, colleagues.
There is a php+apache+ngnix server. Many sites work on one CMS. On one of the sites, with any POST request, we get a 504 error. Requests are different, from 1 to 15 parameters.
Tell me which way to dig?
Thank you.

Answer 1

yandex.ru/yandsearch?text=post%20504%20error
504 Gateway Timeout Error
Most likely your host no longer supports the number of sites. He may be running out of free slots / children