Solved

CD strength doesn't work

What did you try to do?
The CD has Acceleration strength and Fuel economy weakness.

What happened instead?
At the end of season, only the weakness works but the strength does not

Did the problem happen while using wi-fi, mobile data, or both?
Wi-fi

Did the bug happen in the app, on PC, or both?
PC

What operating system is your PC?
Windows 10

Which browser did you experience the problem in?
Google chrome

Can the bug be reproduced?
No

Additional comments:

Was it a 20 race season?

I think you'll find that over 20 races that the starting design of the other attributes would be at 50%, which is also what the strength would max out at, therefore the weakness is more important than the strengths. If you were able to find several a CD with opposite strength and weakness for a 20 race season then the following season you'd have all attributes at 50%;

Oh yeah I forgot about the elite stats cap, thanks for the reminder. Then I request for the moderators to lock this thread asap.