I tried making a forum topic but I never received help, so my next step is to just make ticket, because I'm guessing this is a bug of some kind. Terribly sorry for wasting time if this is not considered a bug, and a problem caused by my own doing.
Basically what's happening is I am trying to implement custom schematic trees into my created biomes, but during testing the trees... well for one only 1 variant out of the 3 schematics I told it to spawn actually spawned (when I used the structure system), and two: they are just spawning wherever they please even though I've specified a block for them to spawn on (grass). I told the schematic to not spawn air or check for room before spawning if that would solve the issue, but it did not. Even when I used the "schematic tree" option in the biome settings, the trees floated and I have no idea how to fix it. Before anything, yes, I have the biome surface set as grass. The schematics are also less than than the block limit.
I'd love to use the structure system, but is it bugged? It either never spawns in the given structures (in this case trees) or it spawns way too many, and disregards the block I have it set to spawn on. On top of that if I have more than one structure that wants to spawn in the same biome, it only spawns one type. I've attached some screenshots of the problem to give a better idea of how the trees are spawning. If this is indeed a bug, please please please fix it. If it isn't, please let me know how I can fix it myself.