Constant lag on voice chat

I've been having this issue for weeks now and is starting to annoy me.

For some reason, everytime i'm on a voice call (either dm or in a server) i have huge lag to the point that my Outbound packet loss rate is with an average of 8%. I called my internet company (Movistar) because I started to lag while playing to and they fixed, but it only got worse on Discord.

I'm tired of not being able to talk. If someone can help me i'll be more than grateful.