A decrease in Google ranking can occur due to various factors such as changes in search engine algorithms, increased competition, technical issues with the website, decli...

Okay, thanks so much for the feedback.

You should consult the website developer for the issue.

If the page is already on the website then there is no harm in indexing. Even you can optimize the page with title-meta etc. to improve the keyword density on the domain.

Declare canonical URL.

when I checked it turned out to be a duplicate page with "index.html" how do I fix it? so there are no duplicate pages

It's possible that your website's ranking fluctuations are due to Google's algorithm updates or changes in competitors' strategies. Sometimes, even optimized websites exp...

the content is not created by AI, every time the position rises it won't be crawled for about 3 days in the future then it will fall again, I'm confused about how to solv...

Check if this is helpful to you, https://support.google.com/webmasters/thread/148310953/google-not-showing-product-prices-in-search-results

It is not required in terms of SEO.