Google Index Issue! Can you help me?

[LinkAkward]

Hello everyone! For the past 3 - 3.5 weeks, the indexes of the articles I have been consistently posting have been fluctuating. When I post a new article, it ranks well initially, but approximately 15 -16 hours later, the index drops. It's quite frustrating, isn't it? Many people attribute this issue to authority, but as I mentioned, it has been happening for the past 3 - 3.5 weeks. There was no such problem three weeks ago, and my authority values were the same. How can I resolve this issue? Have you experienced anything similar? I would appreciate any help. Thank you in advance!