Channel toolbar is not displayed if you go first to an SPA channel

Steps to reproduce:

1. Start with a clean HAP project (saas branch). First login after project start
2. Go to the Channel perspective
3. Select the React CSR SPA channel

Expected result:

The channel loads normally.

Actual result:

The channel toolbar does not load.

Additional info:

JSConsole error(screenshot).
Java console error:

[INFO] [talledLocalContainer] 13:08:54 WARN An attempt to access a protected resource at /hippo-cm/iframe.885a031c856fd806a88d.js was disallowed.

The error disappears if the user opens a non-SPA channel. Then, everything works as expected.

On my machine it also happens on 14.2