Why is http header providing 404 while site is online?

Question

I just transferred my wordpress website from http to https, added easyapache and http2 as well.
Everything is fine and working as expected except for the fact that my homepage is giving response code 404, while in actual it is working fine and online. see here: http://www.designzzz.com Also, i used http status check tools like https://httpstatus.io/ to verify, same thing.
can anyone guide me what could have gone wrong?
Thanks

UPDATE: I just found out the problem wasn't actually with the headers, it was easyapache messing with the permissions, which wasn't letting me clear the cache and invalidated cache file was causing this.

Answer 1

It returns 200 OK for your website, in the browser and on https://httpstatus.io/. Also, 404 response code means that page is not found, not that the website is down. Server errors have codes 500+. You can see all HTTP codes here: HTTP Status Codes.

Answer 2

the issue is almost resolved. so i am going to post what actually was the cause of this situation. As i mentioned above i switched from http to https and started using easyapache .. which created a permissions issue for my wordpress installation.
And due to which older cached files were not clearing/deleting. and it was serving an invalidating homepage cache file.. which was suppose to have a 404 status on clearing. but it was available and stuck.

It also stopped my wordpress functionalities like can't upload images, clear cache, install remove plugins etc.

So here is the solution for such issues:
Either use SuPHP with suEXEC option or use mod_ruid2 or mod_itk. This will resolve the issue. Thanks Ayaz