I used only the 'Cloudflare' and 'Q2A's Cache' functions only. The cache was disabled on Cloudflare. The Memcached, opcache functions are also disabled. It is not a browser cache as well.
I asked my hosting provider as well, they had no clue as well. And today I found out that they had added a cPanel Plugin - LiteSpeed Web Cache Manager. I cleared the cache on it. And my site works fine now.
I asked the hosting provider to disable it.
https://i.imgur.com/iR9Nt7g.png
