Throwing mechanics at higher Trainer levels

I recently leveled up to 38 and it seems throwing has changed a little.

I have to spin the ball much more in order to generate a curve or else it comes out flat, and the ball has even just sailed away a few times.

Also, getting Nice, Great or Excellent seems much more difficult (even borderline ones used to be awarded).

Is this my imagination, a recent change because of the Update, or is this something that others encountered when they hit this level or higher?

Cheers...