Can't walk on moving metro/freight trains

Hello, im trying to spawn trains and walk on then but i cant, my character just cant walk while on a moving metro or freight, heres and example of what i mean have this ever happened to anyone?

Reduce the speed of the train

Nothing, still the same, currently i went from 15.0 to 6.5 and still pushes me to the back of the train…

Any solutions to this?