Pages not indexed

Hello. I’m having an issue with my website not being indexed after using the Rank math plugin and following the setup instructions carefully. My websites have only 5 pages (Home, About, Service, Portfolio, & Contact) and the only home page has been indexed. The rest are ignored.

I tried to troubleshoot by following the steps from this article: https://rankmath.com/kb/google-index/

1. I searched my website name using “site:https://example.com/” and it only shows 1 result and that is the home page.
2. I checked every page to make sure that I don’t set it to NoIndex by mistake.
3. In WordPress Global Settings, I made sure Discourage Search engines option is not ticked.
4. I checked every page to make sure that I let Robot.txt index my page.
5. I did find that the pages have been crawled but not indexed. While I don’t understand why this happens, I made sure that pages don’t have duplicate content.
6. My website has no blog posts so there’s no need for pillar content or internal linking.
7. I manually submitted index requests to Google Search Console every week or so and still did not work.

Despite my best efforts, it seems that it did not solve my problem, and worry that it will negatively affect my business. Can you please take a look into the problem and possibly fix it?