How to draw another render target inside a Scene Capture 2D (component)?

I’m trying to create a World Portal, which might also end up rendering itself given some certain camera angles, so it needs to be able to render the RenderTarget that contains the world. At the moment, all it does is render some kind of nothing. It’s hard to explain what it actually does, so attached is a video of it.

How do I solve this issue? I’ve attempted the following:

  • Use a flip-based technique with two RenderTargets used alternatively to render and to draw.
  • Change rendering type from Deferred to Forward.

Edit: Here is the Blueprint

https://drive.google.com/uc?id=1t21-9b6TDKjhmQw8d8HepRCzjJWiVRCR

https://drive.google.com/uc?id=1WryiWyq3vrEb_vwEK_QMVodChdLfyDvP

https://drive.google.com/uc?id=1dx15aJ_IsuixHygdghwpgQ8I4_Sw6c62

https://drive.google.com/uc?id=191jxQIcTlzzpURib4cPrZYOS0C6qNHqW

https://drive.google.com/uc?id=13bRy_ArgZQHChIkvMmHrbzQ5z8MKo_Mt

And the material used

https://drive.google.com/uc?id=1hCuEcaVkrK90E7VR1ymH0SAFkeN6DLHT