Game slows down and accelerates in multiplayer

Hello and sorry for my English who goes through google translation,

I play Forza Horizon 4 on PC for more than 15 days.

In solo play, I do not encounter any problems.
As soon as I’m in multiplayer, whether on a free ride or during races, very regularly the game slows down and accelerates several times and this is unplayable.

I also occasionally get a message at the top of the screen “Poor network status …”

I am running Windows 10 64bit, 16GB of RAM, and a GeForce 1070 8GB and latest drivers.

I also have an internet connection of 900 mb / s.

Can you tell me how to solve the problem? thank you

Speed isn’t as important as latency, how is your latency?

Hi

10 ms usualy