Transitions not working when there is a video on top

I've got a video on a layer that has been resized and positioned to the bottom left (a window of me talking). Then I've got video files on layer below that are there while I'm talking. They all show up, switch, etc. But as soon as I add a transition to them, the entire transition time makes the entire screen (minus the video of me talking) completely black. Doesn't seem to matter the transition type.

If I disable the me-talking-layer in the timeline, then the transition happens and appears as expected.

I will add - the video on top (me talking) is a compound clip

Tell us about your hardware, in particular the GPU, and about the resolution of your timeline.

Tell us about your hardware, in particular the GPU, and about the resolution of your timeline.

Dell XPS 15 Laptop - i7 CPU, 32GB RAM, 1TB SSD, GTX 1050

Timeline 1080p, source clips 4k

Something is definitely weird, when I go into my compound clip and i.e. just move the clip around on the screen and then return to my master timeline, the cross dissolve appears in the empty space (in the corner "window") instead of the entire master screen. Like somehow this compound clip is affecting other video layers