then you're using fake ones, look here for legit ones, I personally use https://leechall.com/ a lot, never had any issue with it. these are the only legit ones afaik, all others are fake
Piracy
Welcome to /c/piracy
No netflix or streaming services landlubbers allowed, this is pirates territory.
How can they break a file they are linking to? Unless it's proxied through their servers
It's proxied. The idea is they buy a premium account on the file hosts they want to support, then request the files using that account on their end and they pipe back the file to you at premium speeds. They have to proxy it or it would be trivial to see that some accounts request files and it gets downloaded from another country.
Then they can resell that as "works with those 24 providers" for cheap and pool possibly hundreds of users per premium account upstream and generate quite a bit of profit.
You'd have to compare the good and bad files in a hex editor and see how they differ, and if it's really corrupted somehow or if you got the first couple MBs with the rest as random padding to make it look like you're downloading the whole file at super fast speeds. Would work for smaller files or the first couple seconds of a movie or whatever so most users wouldn't notice.
In one way it could be a tactic to get you to pay, but at the same time it gives a bad impression of the service. So I'd be surprised if they intentionally did that. It could also just bug out.
Those sites also fundamentally exist to abuse premium accounts on the big file host sites and resell it for cheap. So the file hosting site may be sort of shadow banning those accounts such that it gives corrupted files which the debrid site then happily pass along back to you, at full premium speed. If I was on the defense site that's absolutely what I would do, otherwise they'd know immediately and switch to a backup account or buy more accounts and make it less obvious. It ruins the end user's confidence in those sites and makes it a headache for the admins to even detect when this happens short of users complaining.
Fun fact, debrid comes from french "débrider", "débrideur" which roughly means unleash/unleasher. Those sites originated from french communities often as WhateverDebrid and I guess it's just stuck once it went international that they're "debrid" sites.