Why is the status 404 given instead of 200?

Question

Nginx

Hello, thank you for your attention!
Move: DLE 10.1
.htaccess - standard ( pastebin.com/A7UBskCy)
in robots.txt everything is under control, there are no restrictions.
Site encoding: Win-1251
The problem is that a certain page (one of the categories, the main page of the category) on the site gives a status of 404 instead of the expected 200. There are no problems with other similar category pages.
Browser: prntscr.com/anik9l
Yashin's pinger: prntscr.com/anip21 (in the content of the page he gives the page code, but for some reason in UTF-8 encoding, a bell, but he didn’t understand why).
Own VDS: nginx processes only statics, and scripts (php) - apache.
In php, the default encoding is not set (default_charset no value), in .htaccess it is written AddDefaultCharset windows-1251 because the site is in wine encoding.
It would be possible to sin on errors in the code, but even left a blank page, 404 is given anyway.
Tell me where to dig? For security reasons, I can not provide a link to the site.

Answer 1

Actually the answer was very simple! 404 was issued by DLE itself (despite a lot of text on the "via template" page), since there was not a single "news" in the category.

Answer 2

dig, first of all , in the logs

Answer 3

If nginx gives 404, not Apache (judging by the fact that the error is in the logs of the first, but it is not in the logs of the second), then the problem, I think, is in the nginx config, it processes your page in the wrong location. Maybe there is static in the name of the category or something else? In general, show the nginx config.