Mass De Indexing Issue

Hi Guys, I am facing an issue related to de indexing. My website all content has been de indexed. Now even I am publishing new (AI and plagiarism free) content. That also is not indexing. Even I have submit that url in search console. But still my urls are not indexed yet. This same issue have also seen in some of my friends websites also. Can somebody please suggest me what's the reason for that and how can I resolve this issue? and One more thing the indexing urls numbers of all these sites are in the range of 4-7. For my site or my friends sites or i have seen some other content submission sites which are very older and have very good content. Now all these sites have only 4 to 7 indexed urls total. Suggest me some solution for this issue.