Persistent object cache problems

This was started under my question “How to use wp-optimize” earlier this year. It was marked “Resolved” by someone, but it is not. I just gave up.

At issue was two warnings from Site Health checkup regarding Caching issues. One was resolved by eliminating one of the two Cache plugins I had, down to just wp-optimize. Still had an issue with “persistent object cache.”

This is what Venkat Raj at wordpress.org forum said:

What site health checkup says is to use an object cache. In simple terms, Object cache caches the result of database queries. When the same query needs to be done again, it serves result from cache rather than fresh database query. This is something your hosting provider can provide. Based on the type of object cache (Redis, Memcached) they provide you need to use respective plugin
https://wordpress.org/plugins/redis-cache/
https://wordpress.org/plugins/memcached/

This is what Site Health checkup says, more precisely (details):

Page cache is not detected but the server response time is OKPerformance

Page cache enhances the speed and performance of your site by saving and serving static pages instead of calling for a page every time a user visits.

Page cache is detected by looking for an active page cache plugin as well as making three requests to the homepage and looking for one or more of the following HTTP client caching response headers:cache-control, expires, age, last-modified, etag, x-cache-enabled, x-cache-disabled, x-srcache-store-status, x-srcache-fetch-status.

•  Median server response time was 249 milliseconds. This is less than the recommended 600 milliseconds threshold.
•  No client caching response headers were detected.
•  A page cache plugin was not detected.

Site Health also says that my site “supports APCu”  which is neither of the two Venkat Raj suggested.

I sent all of this into my topic and got no response. Recently, I’ve had other issues and mentioned this again and was told to contact Hosting company (who’ve acted like I was speaking Greek).

Anybody out there have any guidance?

The page I need help with: [log in to see the link]