I’ve not seen or read about this, but perhaps you could specify the sources that you are using (I know you say any, but specifically which ones) also, do you perhaps have a looping delay on the sourced track that is in feedback howl. I often sample tracks I cannot hear, so it may not be obvious, also can you comment on the levels and recorder trig methods etc. I’m curious to try , sounds more like a software issue that ought to affect everyone