Random Assets Not Showing Up in Render View?

I’m having a bizarre issue where I have a scene setup (that I reuse regularly) suddenly start acting odd.

The scene contains several rigged characters & animation, a layered BG and rigged assets.
Today, I added some additional props and such, both inside the rigs and outside.
Everything looked great in the GL View, but upon previewing the Render View, I realized a good deal of seemingly random bits of things weren’t showing up - some old AND new assets/artwork, pieces from inside the rigs and the props.

I thought it might be a Z-depth issue, so I tried moving the ‘invisible’ assets way forward/back in Z-space, but they still refuse to show up in Render.
There are also no visibility nodes or anything underneath these, all just directly connected to a Pass-Through Composite.

(I also don’t THINK the scene is ‘corrupted’ as the artwork is still all very present and functional in my GL view/Library.)

Would anyone know what could be causing random assets to only show up in Open GL view?

Thanks!

(Also, sorry, the work I am doing is under NDA, it might be difficult for me to release the scene file for examination)

This could be due to a lack of graphic card resources but without
seeing the scene it’s difficult to say what in the scene could be causing it.

Make sure every node is connected to the correct network and that your
“Display” toolbar Is not set to “Display All” which could give you a mistaken
impression of how the scene is composed.