Spoiler:
And I've come to the conclusion after a year of experimenting and re-experimenting(Seriously. I'm not even exaggerating.), so it's out of the question that League isn't guilty.
What I'm asking is this: How do I prevent it from swallowing the whole connection without leaving a spare? And for the record, In the whole country, there is but one provider, so it's not an option to change. Whoever solves this for me will unlock heaven for me and dad, and if it's of any help, I think it might theoretically have something to do with maintaining 20ms~ ping. I'm desparate, guys halp