@Ocelot Onesie
I had a feeling, as I had heard others having this problem on random comment sections on Youtube / Reddit. Thanks for letting me know. Will go upvote the main issue report.
@IonEcko
Quick edit: I sat AFK creative floating near the 'spawner' while watching Youtube. My position should have been fine to keep it active. Just wanted to confirm that.
Thats kind of why I was trying it at different height levels...for mob cap reasons. Its why I moved from the ground spawner, to one that moved higher up through the air. I was trying to escape the mob cap.
Though, I have realized my biggest mistake in the rush...I forgot to light up the tops of those higher platforms to ensure the mob cap would stay limited at higher altitudes, and to ensure they spawned UNDER the platforms, and not on top as they had been.
They seem to prioritize open air over anything with a roof at least 2-3 blocks high. But they do eventually spawn beneath there after a time. Found that out this morning after waking up (I had been testing this til 2 a.m - which probably didnt help things).
So not a bug, I guess, but a definite tweak to the way mobs spawn would be nice to see. Honestly just more parity with Java in general would be nice to see, haha. But thats another tangent.
Still gotta figure out if trap doors still work for creeper farms though, as this was the entire point of my experiment, and I keep hearing mixed things online.
Closing off, I should probably close this bug report. Still would like to see tweaks to mob spawning behavior on bedrock, but I cant say this is a bug any more.
@Max H
....
That probably would have made testing so much easier. I don't know why I didnt think of that. Guess I was trying to keep things 'natural' but even so, that would have worked and made testing much faster.
I feel like a dumbass lol.