|Your internet works properly at all other times except for when you run this software...right?|
If the issue only crops up when you're running that software so it seems likely the software is the issue. Perhaps it's misconfigured. I would talk to another gamer who runs it, and for whom it works properly. Find out how they have theirs configured and then I'd uninstall, and reinstall/configure the software.
If that doesn't fix the issue, I don't know what else to tell you other than, "don't run it if it doesn't work properly"
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.