I've pointed a domain to my network using an a record, and mapped the domain to the right site.
When I go to mysite.co.uk, I get redirected to the 123-reg.co.uk holding page for the domain, but when I go to mystite.co.uk/any-page it works - it's just the homepage that doesn't.
Normally I'd just assume that the changes are taking a while to the a record, but confusingly, it seems to work for a short time, the go back to the 123-reg page (i.e., mysite.co.uk worked for a few hours, then stopped working). This seems to be the case on other devices too, it works for a while then seems to point to the holding page. I've tried clearing cookies and browsing data, but I still have the same problem.
To add another spanner into the works, if i head to the page in an incognito tab, it works just fine!