My bus is jumping everywhere~!!!

Hi guys I've just installed OSMI for a try, but I found the bus always jump in most situations.......probably like a kid, especially when the bus step on the rocky surface and when the bus is staying nearby a bus stop boarding passengers.....the bus still didn't stop jumping when i started the game in berlin bus depot..... did anyone also experience such problem? or anyone know what's happening there? Thx~

Go here:https://omnibussimulator.forumieren.com/t3698-problem-omsi-very-and-many-stops

and use these specs that i said to ruicp and then say something