Command + C doesn't copy in Chrome on hosted JIRA

Using command + C (cmd+C) to copy text when browsing an issue does not work. This applies to any text in the page. The pasteboard retains its old content.
Right-clicking and selecting "Copy" works.
It works fine on issues on jira.atlassian.com, but on our own onjira.com installation, it does not work.

Disabling the JIRA keyboard shortcuts does not work around the issue. Other users of our onjira installation are experiencing the same problem with same browser.