I had to exemplify your website and the other website name but for your and readers benefits, I can disclose that:
- both domains (yours and the other domain to which the strange URL redirects to) have the first part of the IP address the same and only the last three digits are different (i.e. aaa part is the same: aaa.aaa.aaa.nnn)
- both sites are hosted by the same hosting provider
I therefore believe that there is an issue with hosting setup and I suggest you contact your hosting provider, explain the issue and ask them to fix the problem.