Ketan, I'm on Plusnet & W10. All OK on Opera, Firefox, Avast, Chrome, Edge & Pale Moon browsers.
I'm also using a BT home hub, which has a fixed DNS of;
Primary DNS:213.120.234.42
Secondary DNS:213.120.234.38
I think Plusnet's default DNS server address may be different.
I've had issues in the past, where, following a website's udpate, there was one or more DNS servers which failed to resolve the address, until at some point they were later updated..
This meant that some people on a particular ISP could access a website, but others could not without changing their default DNS server address.
Bill