HTML Overlays not rendering correctly on Caspar

I am working with Overlays that come through a URL.
I add them using the HTML Page, in general I have no problems and everything looks very good but when I use graphics that have information that comes from an RSS or a Google Sheet that information is not shown in CasparCG.
I have done tests to see that this URL was correct in Chrome 71 and outside of CasparCG everything is normal but inside it no longer works.
Any idea what is happening?
Thanks in advance