Google Indexing cURL 28 error

I have a website in Wordpress and I am showing a sitemap to google with about 6,800 urls.

Some days ago there were 6,750 urls indexed. Today there are about 500.

Webmaster tools reports:
5,000 urls sent and indexed (this has been constant for a while now)
1,800 discovered and not indexed: Excluded

The excluded urls are not blocked in robots.txt or have a noindex follow tag. I tested some of them in google page speed insights and it reads the urls.

SEO Yoast health tool sais there is a CURL 28 ERROR that reads the next:

"Ryte offers a free indexability check for Yoast SEO users. The request to Ryte to check whether your site can be found by search engines failed due to an error.

Error details: cURL error 28: Operation timed out after 5001 milliseconds with 0 bytes received (http_request_failed)

If this is a live site, it is recommended that you figure out why the check failed."

So I investigated online and found this 5 points to check with the server:

• Make sure your server is running a recent version of PHP and the cURL library.
• Try to increase your Server Memory Limit settings.
• The cURL error can be a dns related issue. Your hosting company might need to switch dns configuration to OpenDNS
• Ask your host if there is some limitation with wp-cron, or if loopback is disabled.
• Ask your host if there a firewall or security modules (e.g. mod_security ) that could block the outgoing cURL requests.

I checked them all and they say everything is ok. They just increased the memory limit.

I am not sure if this cURL 28 error could be causing an indexing problem with my site. What do you think? Any Ideas?

Thanks.

 

Code 28 is a timeout. Most of the time this means that your server is either ignoring the request, or simply takes too long to serve it.

The former is typical of being blocked at the firewall level. Have you implemented any sort of anti-spam or traffic analysis that may have done this?

The latter is often just a matter of bad server configuration or poor choice of software. Given that you're using mind-numbingly dumbass broken slow trash like turdpress with its equally derpy re-re trash like Yoast... well...

I'd have to see the site in question to weigh in further.

That said, sitemaps? If your site is well formed with no dead links and all pages properly cross-linked, a "sitemap" is placebo bullshit that does not one single blasted useful thing.

 

CURL error is not "your" issue.
The site where you were checking speed etc, that site did not got a response from your website, hence the error.
You need not change anything for PHP or CURL on your side.

Basically, it could be downtime of your website or very very slow speed causing this issue.