Vehicle dose not accelerated after reaching 40kmph even if throttle is full

I am trying to run a acceleration condition with our teams vehicle. Everything runs as expected till the vehicle hits 40kmph after which the throttle remains 20% for a while and suddenly reached 100%.Even though the throttle is full the vehicle does not accelerate. What could bethe issue.I tried with diffrent drivers as well as powertrain configs There was no major diffrence. Please Help

Hi fcm.user_26
Did you create the TestRun or using one given by IPG? Could you share your TestRun and Vehicle? It would be easier to check