Premiere and Encoder export glitch frames

I've been trying to export some greenscreen footage along with text and some simple animation within Premiere pro. But it's been giving me glitched frames here and there. And the thing is every time it appears at a different time. I've checked my timeline and any don't appear in my edit. Does anyone know the solution to this?

I am on an 2017 Intel iMac and my Premiere Pro build is 23.0.0 (build 63) - I can't upgrade due to compatible issues with other editors. But I've put the project on the lastest Premiere Pro version and the problem only gets worse. 

Here's what I meant by the glitched frame: