Moved Site and Visitors are Automatically having URL Error

I recently migrated my site from one host to another without making any changes at all. The complete CPANEL was migrated.

All the links are working well and the site structure is intact.

However, in the visitor log I can see visitors going to URL/null

e.g The URL is sitename.com/how-to-invent/ but some visitors (not all) are being taken to sitename/how-to-invent/null.

How can I fix this. Thanks in advance for your help