have never noticed that issue as when i view a GP i make sure i have time to view the entire GP in 1 sitting.
However i have noticed a different bug. This is when i've been racing in the GP3WF1L and when i finish the race. i pause and run the replay to the flag to get my race total time and fastest lap.
Once i've got these i exit to the options menu save these and then return the the game to exit out properly.
However when i return the race time i wrote down and saved doesn't match the one up on the results screen before the game exits to the reace results or after when i check the full race standings.
I'm not sure if this is GPx or the actual game that is at fault but it would be good to see this fixed (if it's GPx)