Well this would be a bug to me because when you try to fix that (say by using the mixer track pan knob), it should also work and it did not here.
You should not need to send a cc command manually again, whatever you set with the mixer (or better maybe the mixer pan should be at least updated with latest value) should work.
What is even worse in my case is that using the mixer track pan does not fix the problem, aside from the fact that it still displays a stale pan(= midi cc 10 btw) value (i.e. centered as before the AUtoLFO went in action).
Also, please note that even if you perceive a change say, by changing the pan the opposite direction from the mixer track after disabling the AutoLFO (i.e if it were left go completely right) you can notice it is actually not panning properly ; you still hear only right but the volume is super low, indicating that it accumulated the latest LFO change in the pan with the mixer track change you did and in series, instead of doing an absolute change in panning. To ensure you understand this somehow subtile panning difference, please save then exit and reload the same song you’ll perceive easily a difference and it should not be the case for that track pan and volume values.
I certainly truly appreciate your feedback and testing, but I’d be interested to get a steinberg representative feedback on this (from developer to developer lol)