Website deindexing

My website content is constantly getting deindexed from search engine.

I’m not sure why this happened but I did two major changes few days ago before I noticed this problem.

The two changes I did are:

1. I upgraded from free rank math to premium. But after installing the premium version of rank math I realized the free version was already too good for me, so I uninstalled it in about 24hours later

2. After uninstalling premium rank math, I changed my international targeting in search console from unlisted to United state.

These were the two major changes I did.

24hours after these two major changes were made, I noticed that:

1. Site map discovered url suddenly showed zero

2. My content started getting deindexed from SERP. My mobile friendly pages started reducing and currently it has reduced to 1. My FAQs rich snippet data started reducing too and currently it’s zero.

I don’t understand why these is happening.

But if I submit the child version of my sitemap it will show all the post and pages successfully but the primary site map is showing zero.

Also, the majority of my content has been deindexed from search engine. Only about 7 post in left in SERP and the deindexing continues every day.

Note:

1. I’ve tested my sitemap it all seem to be working fine, I’m not sure why this suddenly happen in GSC

2. My content are original and quality

3. I haven’t engaged in any link building

4. There’s no warning or manual action warning from google search console

5. My site speed is almost 100% and responsive too.

I’ve checked everything I could, I’m not sure why this problem is happening.

Please any help or advice will be greatly appreciated.