Cache being purged leading to 10seconds TTFB slow site

WPO will do a partial purge in the following circumstances

When you publish new content or update/edit existing content, the cache for that post/page will be cleared, as well as associated content (category archives, blog archives)

When comments are approved, or their status changes

When terms are created or updated

When changing/updating stock quantity of WooCommerce product or product variationWhen updating the ‘page_on_front’ option

When updating ‘page_for_posts’ option

When updating the ‘URLs to exclude from caching’ WP-Optimize caching configuration

When trashing a postWhen running importersWhen WooCommerce product is on sale (Premium)

Did the purging of the cache happen after you had updated anything.

I checked some of your product pages with Page speed insights and your page speed was excellent, for example;

https://pagespeed.web.dev/analysis/https-www-hypres-co-uk-gbark-optimize-product-buffalo-horn-medium/rbew3dkyin?form_factor=desktop

HI, thanks for getting back to me.

It’s not so much the page speed on none cached product pages. It’s the page speed on none cached product category pages.

The category pages cache is being purged regularly, and I do not know why. When the product category page has no cache, the TTFB can be anywhere from 6 seconds to as bad as 24 seconds,

From today’s tests
https://ibb.co/4shc5yp
https://ibb.co/Yk9k67T

this is a staging site, so no product details, or stock levels have been altered, yet, the cache on product categories is being purged several times a day.. any help & advice is greatly appreciated.

To me it looks like all the request are coming from the minification/ minification cache

Can you try deactivating minification and see if the issue persists.

Also if you are merging your CSS and JS (it looks like you are), deactivate this as your site support http2 and it will be slowing your site down.

Thanks for this, I had added /product-category/* to the excludes list, but i will remove and try your suggestions and report back

??

It’s not made a difference, still slower load times on non-cached product category pages than excluding them from the caching…

https://ibb.co/NrJRD9b
https://ibb.co/YXJnLTJ

As an aside, it looks like your theme might be automatically minifying your files, I would only allow this either in your theme or in WPO.

Excluded pages are non cached pages so I would expect these to have a slower load time than cached pages.

Can you install the free plugin WPCrontrol and take a screenshot of CronEvents?

In the setting of WPO can you export your settings and upload them to something like WeTransfer. I can then upload them to my site and get a good idea of what your WPO setup is currently..