Virtual host configuration getting deleted automatically

Hi,
I have two domains abc.com and abcd.com. when I open abc.com, it opens abcd.com instead of the original.
When I check nginx virtual host, configuration for abc.com is missing and found that file in nginx_OLD folder.i have copied the file to nginx directory and rebuild domain config then the site abc.com is works fine..after a day, the same issue happened again and I repeated the step again to make work.But the issue repeating again and again automatically . What could be the reason ?

Hey, try to rebuild virtual hosts via CWPadmin => Apache Settings => Main domain conf