Here today, gone tomorrow, and back, and again gone?!?

What is the deal? Does google intermittently index new content? Or is there something else going on? One of my posts was getting on page 1 immediately, only to disappear, then reappear and then disappear again. Some things I should point out, these blogs polished by being rewritten by AI, but the quality is still as good as any of my articles written from scratch. My website also doesn't have a passing score for performance. On PageSpeed Insights, I do typically see a performance score of 45-55, but accessibility is decent at 75, and best practices and SEO are at around 100. My sites domain authority is 20. So, is this intermittent indexation a normal thing or is it something I can control and it's happening for a reason?