Unexpected blank scenes, can't be deleted


In this image, above Cue 169.9, there is what appears to be a Scene with no label. If I run [Cue] [169.9] [.] [9] {Attributes} {Scene} [Enter], it doesn't change, and if I run [Cue] [169.9] [.] [9] {Attributes} {Scene} Scene 123 [Enter], it adds another, real, Scene below the blank strip. Everything I've tried suggestes it's not a scene at all.
There are about two of these blank strips in the cue list (we only have one cue list).

What are these weird blank "scenes", and how do I remove them?

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