Motion Blur Error / Weird Glitchy Behaviour...

I'm trying to use motion blur, but it keeps looking like this (see attatched file) Sometimes it works though and looks normal. Kind of random. Am I missing something?

Windows 10, 16GB ram. Nvidia 1070Qmax

Hi again,

I have tried again in a completely new project - same thing happening! Even without the motion blur parts of the text appear in random places at random times. I don't get this... Can somebody help please?

Well... So it's back to Adobe for me.