Expired domains tend to be more susceptible to penalties such as the "site domain on Google only shows 1 2 3 4 5 7 9 11, etc." This is because people have used expired domains for spamming, leading Google to develop methods to identify and penalize such practices. Additionally, low-quality content like AI-generated or poorly translated content can contribute to penalties.
It's important to note that not all expired domains will be caught and penalized; it can be a matter of luck.
To assess the situation, I recommend performing a Google search using the "site:domain.com" query and observing the number of search results. You may also find relevant information in the thread you mentioned.
Certainly, it's possible that not every case involves a penalty, and the fluctuations in your domain's search rankings could be a normal part of the search engine dance. When launching a new website, it often takes a considerable amount of time, typically several months, for it to establish itself and stabilize in terms of search rankings.