Animation causes environment to flicker

I have a sequencer cinematic set up with a train animation that passes the camera. On the last frame of the train passing the camera most of the environment meshes go invisible and then come back like a flicker. It only happens when I have the Train anim in.
Any ideas?

are you maybe using TemporalAA as your antialiasing method?

Yes I 'am, do you reckon that might be the problem, If so what method would you suggest I go with?