As far as why the downloads are failing - does the site/mirrors your downloading from have subscriptions for higher speed downloads? My bet would be that if you’re downloading without a subscription then your traffic is getting deprioritized server-side. Kind of a shitty way for them to operate, if so, but nothing you can really do about it. Most sites I’ve downloaded from like that just make you watch an ad or force you to wait some amount of seconds before the download starts. Just my hypothesis, though. Can’t know for sure if that’s happening without knowing what site it is.