Somehow Discord's audio is interfering with the process of decoding. I don't know what it is. Perhaps some of you had the same issue but didn't realize it.
I disagree about this being a radio interference issue. Something is either causing delays in the audio output from the SDR program, or delays in the fax decoder reading the audio input. Could be an overworked CPU, could be buggy interrupt handling.
Somehow Discord's audio is interfering with the process of decoding. I don't know what it is. Perhaps some of you had the same issue but didn't realize it.