Throttle in automatic gear shifts

1.6 16v 206 xt electron gas throttle
The vehicle suddenly throws gas at high speed during gear shifts
When it changes from D to r, it gives a very hard transition between gases.
The vehicle does both with petrol + lpg and sometimes the fault improves.

Last month, when I was buying a second-hand car, I showed a 307sw to the authorized service, and he had the same problem. the service said that because of this situation, chances are that it should be a rectification,