Terrible FireRTC Connection

Not sure if this can be fixed or if it’s just my connection, just throwing this out there. Every time I attempt to call a scammer, my voice gets terribly broken up. But when I call my own phone to listen to how it sounds, it sounds perfect. What could be going on?

Here's a good example of broken voice:
https://phone.firertc.com/calls/5b66253e74756370b3980000/recording
Also a fairly good call on the scammer's end lol

Just called them, it’s fine for me, but it sounds like they’re very wary of scammers

https://phone.firertc.com/calls/5b662a807475636e29ab0000/recording

EDIT:

Called again, still fine for me.

https://phone.firertc.com/calls/5b662b257475637100c10000/recording