I can confirm the issue is because of the FIR output sample rate change on the channels Export tab.
Thank you for this response.
It makes sense now that you explain what FIR D is looking for.
This kind of makes some sense now. The measurement is hi-res data from a 4pi room and I chose to ignore phase and time(We do our processing for time windowing) However, the magnitude is displayed correctly. And since Auto Mag should be trying to work on matching measured magnitude to target only, I do not see the relation to phase.
In any case, it would be helpful if the application showed an error message upon import.