It's probably a server-side error (sloppy scripting or a badly organised pipeline between the sound files and the server and the internet), which means it occurs regardless of your connection. It wouldn't surprise me, that said, if the glitch also occurred client-side. I think we'd need to ask @Bjarkehs for more or better information.
"fordi" means "because".
"why" is the opposite of "because".
Let's say I replace "it" with "I am buying meat." I can say "I am buying meat, because he eats meat." but I could not say "I am buying meat why he eats meat." The fact that he eats meat is why I buy meat and not the other way around.
I know in some languages "because" and "why" look similar, but they usually have some small difference, for example: "Por qué" is "why" in Spanish and "porque" is "because".
I think that would be "Det er derfor, han spiser kød." or "Det er grunden til han spiser kød." ("grunden til" = "the reason for") https://en.wiktionary.org/wiki/fordi