This has been answered via support@eventide.com.
But for others who are interested:
It is not possible to say for sure what happened – we have replaced a few of these but not a lot.
Most likely are differences in the grounding of the two connected systems. Hot-swapping is worth avoiding. The fact that the previous setup did not do this suggests that it is a connection issue.
FireWire is pretty much obsolete now, and will probably go away entirely with ARM macs and OS11 (or the next one) – AES might be a better bet.
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