Reverseproxy and VHOST incorrect in CSV results

When I go to scan machines behind reverseproxy, the results are associated with the wrong vhost.

for example (the real case):
321.321.321.321 a.example.ex → no vulnerabilities
321.321.321.321 b.example.ex → Apache Tomcat 7.0.1
321.321.321.321 c.example.ex → jquery 1.0.1

in the CSV result vulnerabilities:
321.321.321.321 a.example.ex → jquery 1.0.1, Apache Tomcat 7.0.1

What am I doing wrong? Can you suggest me a configuration?

Thank you