Cannot convert camera to spawnable state in sub-sequence

Convert camera in sub-sequence to spawnable will cause this camera cut turns into a totally blocked state. But the same operation in level sequence is totally fine. Why?

I feel like i’ve done that before

does the camera cut track point to a camera in the sequencer?
and then in another new sequencer you add a shot track
and load the first sequencer into the new one

I can’t do that because level sequencer is generated by others in bulk through scripts, and while this works but manually modifying such a large number of the sequencer I don’t think is appropriate.

I had a colleague scripter work on importing stuff into sequencer, there’s some weird stuff that goes on with the imports to force refresh the sequencers and a couple gotchas
so you may have to play around with the sequence of how things being imported.

also with python he found that there was a lot of stuff not documented, so he had to dig through documentation to find things. my python is garbage so I can’t speak to it
I just remember where he bumped into issues for that sort of thing