I'm having some issues with scratchy/crackling audio. I'm on MacBook Pro with Zoiper5, the latest Catalina update, fast internet, Sennheiser USB headset. I've tested both wifi and ethernet in 2 different locations, tried 2 different mics, and I'm still experiencing the same problem. Zoiper is showing ideal statistics (3-4 quality, jitter under 50 ms, 0 packet loss). Disabling echo cancellation and noise suppression seems to help a bit. I'm at a loss...any suggestions?