Unable to run wordpress on .co.uk domain

Hi all. I have been trying for more than 5 days now to get a domain to work in CP. Steps:
1- Add a domain to CP with extension: .co.uk like mybusiness.co.uk for example
2- Setup DSN in Cloudflare and use NS of cloudflare in CP in the DNS records
3- Install wordpress in this xxxx.co.uk domain

Now when you try to open the website, it’s going to either 404 page, or strangely, launch another website on the CP server. I have disable openbasedir security, modsecurity. I installed wordpress manually and also by using the installer in CP. The public_html folder has all the file, but it will not open wordpress.
Domain with extension xxxx.net or xxxx.com work fine.
Anyone running domain in CP with .co.uk extension? Or what could be the problem here.
Many thanks

do not use php 8.1

That makes it sound like an SSL issue, have you issued an SSL certificate for the domain that is having the problem?