Hi Steve, if you're seeing the 'no change' result, your drivers are being randomly trained in an area which they've maxed their attributes in. You need to change which area you are training your driver in:
If you're in the app, tap this button to see these options:
Nope, I've got it sent to driving ability only, and nothing is above 11, so nowhere near max
I have tried to reproduce the problem on your account and did not encounter the 'no change' response. Which driver or drivers are you seeing this happen on?