thanks for the data, I had a quick look. There is something strange about your system.
When enumerating audio devices the audio engine only detects:
=>Built-in Audio;Built-in Audio
=>Instant On Sound Effects;Instant On Sound Effects
One time it also tried to set the current device to
OWC Thunderbolt 3 Audio Device
but then immediately set it back to Built-in Audio.
This is strrange, because the thunderbolt device did not get enumerated in first place.
I don’t know that device, is there an ASIO driver available for it?
Also, later in the log file I can see many many ‘overload detected’ messages.
These messages come from the audio engine when it detects that it has more
audio data produced than the audio driver can actually shuffle to the outside.
So it is no wonder that you experience that quirky audio result.
As to why that happens, I can not say at this stage.
You are running at a buffer size of 256 samples. How about if you go to Edit > Device Setup,
then choose Device Control Panel and change the buffer size to a higher value?
Does it get any better?
I need to discuss on Monday with other engineers, especially the Mac specialists
and see with what other suggestions they come up with.