Collabora office copy/paste | Content Security Policy error

I have a problem for a long time and I can’t solve it. When editing a document with Collabora Office, I cannot use copy paste or download the document via File>>PDF Document. In the browser console I get the error: Refused to frame ‘’ because it violates the following Content Security Policy directive: “frame-src ‘self’ blob:”.

I am running Pydio cells and Collabora Office on a reverse proxy. I am using the CODE version of Collabora Office on it’s latest version (Pydio Cells is also running at the latest version).

I hope someone can help me =)