I understand your frustration, a couple years back when i was actively working with 3d models and monogame, i’ve had similar problems.
Back than the solution involved switching to an older Blender version (v 2.68) because in v 2.69 they switched their FBX exporter and it wasn’t working with XNA/MonoGame.
I’ve also wrote a custom pipeline processor for the models, so i could load them directly into my model structure. But as i said its been ~2 years so I’ll need to verify the whole process (Blender (v2.8 hopefuly) -> fbx -> pipeline -> game) to see if it still works, than i can write a guide/tutorial to help you (if noone does it sooner). Just gimme a few days and i’ll get back to you.