Dave pointed this out. It seems that the segment 1 of the EY ASC TR B QPD railed after 18hours of the current lock. I'm guessing that we aren't using this PD during the lock, but there is a clear drift to its rail/saturation point. Trending a bit back, there are a few small times that will saturate, but nothing for this amount of time (going on ~7 hrs at this point).
I attached a trend of this lock with all four quadrants. I guess the other odd bit is that SEG3 has drifted to near 0, so we must be moving off this PD.
Might be nothing, but worth noting here.