I quit bowling for about 25 years. When I started back my grip had shorten by about 1/4". I have been having trouble when bowling in league that in the second game the ball does not feel the same as it did to start with. Today in practice I realized the same thing was happening. I put my hand in the ball an realized the problem was my span had changed enough that I could now put my fingers in to semi finger tip where when I started it felt slightly long. I guess there is nothing one can do unless they have balls drilled with different spans. I tried shortening the span to see if that helped but it did not. Ever had that problem with someone?
Can't say as I have.
Are you using a 25 year old ball/fit?
If so, it surely doesn't fit you the same as years ago. Redo the entire fit for your current flexibility, texture and desired effect. You've changed, your ball fit MUST too. Thanks for the question.