I have a part that, for some reason, goes way out in the weeds when I add it to an assembly. I can't figure out why it's so far away.
The green part is the problem.
If I rotate the view more, the part is so far away I can't see it with the model also in view.
I had the exact same problem, and some tips I received in this thread helped me:
Inserted Parts Are Placed Far From Assembly, specifically the one I marked as "correct" worked for me.
I still am not perfectly clear on why it is happening. In my situation it seems to do with the fact that my "in the weeds" part was made from a sketch I ripped from Autocad. In Autocad, the "drawing sheet size" that surrounded it was giant, and it gets imported into SolidWorks almost as if it is part of the SW part itself. Not sure if that is where your part sketches came from, but that is what happened in my specific assembly.
Hope that helps.