Hello,
I had a quick look and didn't notice anything that could explain this, except maybe the Attrition level.
Could you change this line in your Tennis.ini, under [TrainingClub], from : (HowTo =>
topic19-32161.php )
Attrition = 1.0
to :
Attrition = 0.5
and tell me if it makes the fps drop in the Training Club as well..?