Problem Pentaho 9.1 when using CDE Dashboard

Question

I have a problem in an installation of Pentaho 9.1 that I have made in our environment, and it is the following.

I have successfully installed Pentaho 9.1 CE in our environment, following the documentation correctly. Since we have an nginx balancer in front of us to redirect the requests that are made depending on which applications, send them to the corresponding web server.

For our Pentaho installation, we have changed the URL path, so that instead of accessing through http://servername/pentaho we access through http://servername/apps/dashboards/pentaho. The only change that has been made in Pentaho, is to change the path within Tomcat so that it takes this URL by renaming the folder where Pentaho is contained to apps#dashboards#pentaho.

In this way we correctly access the changed URL. But we have a problem, and that is that when we go to access the CDE plugin to generate dashboards, we see that it does not load and we cannot do anything. Opening "Developer Tools" of the browser (firefox, chrome...) in Console, I can see the following errors:

XHRPOST http://example.com/apps/plugin/pentaho-cdf-dd/api/syncronizer/syncronizeDashboard
[HTTP/1.1 404 Not Found 47ms]

XHRPOSThttp://example.com/apps/dashboards/pentaho/api/repos/pentaho-cdf-dd/tmp/.cache/lang/messages.properties
[HTTP/1.1 403 Forbidden 53ms]

XHRPOSThttp://example.com/apps/dashboards/pentaho/api/repos/pentaho-cdf-dd/tmp/.cache/lang/messages_en.properties
[HTTP/1.1 403 Forbidden 53ms]

XHRPOSThttp://example.com/apps/dashboards/pentaho/api/repos/pentaho-cdf-dd/tmp/.cache/lang/messages_es-ES.properties
[HTTP/1.1 403 Forbidden 52ms]

XHRGET http://example.com/apps/plugin/pentaho-cdf-dd/api/plugins/get

You can see that when you access File > New > CDE Dashboard it doesn't load because it doesn't build the full URL correctly, and that's why it returns a 404 on some calls.

How can I solve this problem?

Best regards