Base URL changes after importing a Cloud site

Steps to reproduce:

1. In Cloud, Create Site Export
2. Import into 5.10

Expected result: base url and port will remain 8090 (or whatever currently set to)

Actual result: Base URL port changes to 8080 (JIRA default port) but actual Confluence port (in server.xml) is stil 8090 and accessing many URLs fail until base URL is updated.