Strange FPS Issue around NYC w/XEnviro

[pegruder 65]

So I've had this issue lately with FPS dropped to 1-3fps flying in to the NYC recently.  I was running XP11, the latest JAR A320, Xenviro 1.04(1.06 has some issues in FlyInside) & lastly, running this in a CV1 Rift with FlyInside.  The entire flight was uneventful, taking off from SJU which was partly cloudy, cruised, and started descent.  Soon as I started to make my right turn crossing SIE to continue via the CAMRN4, the sim choked, dropped to 1fps, and kept bouncing between 1 to 10 erratically.  It only seemed to clear if I turned my head towards the east away from land and kept it there a few seconds.  What's strange is the weather wasn't anything crazy, only partly cloudy at the time so it wasn't an overload of clouds to draw.  Soon as I disabled XEnviro it seemed to clear and FPS restored to around 25-30.  What's odd is if I load the sim in JFK for instance, I don't have this problem.  Was this a bug since I was using an older XEnviro or some other anomaly?