Suddenly position drop on Google [duplicate]

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  • How to diagnose a search engine ranking drop? 5 answers

I manage a website last year, and suddenly (after August) we faced a problem with our position on Google.

seo problem

On August we dropped down to 85th position, so I rerun the website seo (with Yoast addon) and finally we went after 1 week at second / third page. But yesterday and today, without any changes we have dropped down again at 8th page.

I want to inform you that I am not seo expert, so please let me know what I have to do next, or what tools to use / learn.

Thank you!