but “playback stopped because the data did not arrive in time”.
This is the most suspicious of all because this is just software (setting). Not that it is intuitive, but it is. And I bet you that this is since people are telling (you) a different SFS than 140.19. For example, 70.19 gives exactly your problem, while 80.19 works. And someone (Robert) suggested the 70.19 ...
Then switched OFF and ON the NOS1 and music plays, but very distant.
If possible this is even more suspicious because it tells (to me) that you did not check the DC Offset, which, mind you, is quite consistently at the "1/-1" position after switching off/on the G3 version of the NOS1a (or reboot the PC or replug the cable). So earlier on you told about this all right, but this time you omitted the checking for this ? And switch off/on a next time and it is fine (also quite consistently).
Nothing is broken (I think) but you broke in to a relatively long time of "it works at this setting" and now suddenly all is "unknown" at changing something.
I had the same this week, up to rebooting by Audio PC which did not help ...
I can't guarantee it, but ...
Let me know how you fare.
Peter