VFS does not always serve the latest attachment version

Steps to reproduce

• Attach file test.zip to Sandbox.VFS.WebHome
• Insert vfsTree macro:

  {{vfsTree root="attach:test.zip"/}}
  

• Modify content of test.zip by adding a folder to it.
• Reload page.

Actual result

The tree does not show the new folder, even after a forced refresh. When visiting the JSON tree URL, the JSON of attachment test.zip contents in version 1.1 is obtained, without the folder added in version 1.2.