Why no padlock link for your reference.
Your site loads with for me (clear your cache/try using a different device/network/browser), however you should be aware that by using Flexible, your site is not fully secure and it can cause issues with WordPress.
From Google Chrome: https://prnt.sc/phj2hj
Would you please suggest, what to do?
That looks like a DNS caching issue on your end, seems you are going directly to your server and not through Cloudflare. It should sort itself out. Still loads fine for me.
Also to reiterate, this means that your site is not fully secure.
You were right. That is due to dns caching of my ISP. They are using custom dns, not google dns and I checked with nslookup and it is showing me cloudflare dns. I hope it will resolve soon.
Thank you for pointing that out.