I had quite a similar experience. For the 1st 4000 miles, would regularly get to 242 - 244. Then for next 1000+ miles when charging, it would get 239 max. I took the charge down to about 10 miles left, and did a proper 90% charge on a NEMA 14-50 (instead of HPWC) and voila, back to 242-244...