Embedded adding two semi colons to report container iframe

[S-J-D-13]

I am developing an app using power bi embedded, everything was working perfectly but yesterday two semicolons started appearing in the top left of the report container. I haven't edited my code at all and they weren't there a few days ago. 

If I change the background colour to default they disappear, but when I use transparent they appear. 

I am using this to reference the client library: 

<script type="text/javascript" language="javascript" src="https://rawgit.com/Microsoft/PowerBI-JavaScript/master/dist/powerbi.min.js"></script>

Any ideas on how to get rid of them?