Hi, @marco-baldan. It appears there are two A records for the apex domain:
designbath.co.uk. 300 IN A 99.83.190.102
designbath.co.uk. 300 IN A 75.2.60.5
That first record for 99.83.190.102 does not point to Netlify and that record should be deleted if you want the site hosted at Netlify.
Also, there is an inactive DNS zone here:
https://app.netlify.com/teams/marco-baldan/dns/designbath.co.uk
The domain is not using Netlify DNS:
$ whois designbath.co.uk | grep -i "name server" -A 5
Name servers:
ns-1491.awsdns-58.org
ns-1958.awsdns-52.co.uk 205.251.199.166
ns-489.awsdns-61.com
ns-531.awsdns-02.net
Inactive Netlify DNS zones are not recommended nor supported:
For this reason, the wrong A record and the inactive DNS zone (both) should be deleted. Doing that should resolve the issues here.