Rendering a RenderTarget inside another RenderTarget?

I’m running into an odd issue where a SceneCapture2D(Component) will not render a RenderTarget2D created by the same object and instead opts to draw what looks like drawing a NaN value. The region where the RenderTarget2D should be is simply a copy of what the scene before it was, as if nothing had been drawn at all, but it still draws anything else I put over the actual texture. I’ve linked a video showing how it looks like below.

How do i solve this issue? I can easily do this in any other engine, but Unreal Engine 4 seems to really dislike having other RenderTargets rendered inside another RenderTarget - I’ve even seen it straight up reading from another render target for no reason other than that it wanted to.

What I’ve tried so far is to use a double-buffered RenderTarget, flipping between which one is drawn and captured, and using a capture-and-copy style RenderTarget approach. Both ended up with the same result.

Links

I was able to do this in UE 4.15 and now I upgraded the project to 4.19 and it is not working anymore. Had you found a workaround for it?
If not it would be great if you can submit a bug report, you seem to have it laid out pretty well.
This trail effect is what is now broken for me: https://twitter.com/TocoGamescom/status/984060184489283585