Custom Code Block Cutting Off Text

Hello,

I put a WebGL game onto my website, the problem is when I put the code block in between text, the bottom text gets cut off. 

Here's a video showing the problem.

https://youtu.be/rHMwx5PiS3o

You can see when I edit the section, the text below shows up. When I save it, it shows it how I want. The moment I refresh, the text goes away. 

I have no custom code anywhere else besides the code block and can't figure out why this is happening.

<iframe src="I HAVE A URL HERE" overflow:hidden;
width="98%"
height="720px"
title="DodgeBlock"
scrolling="no"
overflow="hidden"
overflow-y="hidden"
allowfullscreen="false";>

This is the code in the custom block.

If anyone can help that would be great, thank you.

EDIT: I also tried changing all the "hidden" values to "visible", but that didn't work either. Also tried enabling scrolling, that also didn't work.

EDIT 2: If I put the code block below the text with nothing below the code block everything shows up, although that's not exactly what I'm looking for.

Hi,

Can you share link to page where you use Code Block?