Font changes when outputting logs

I've recently set up my log templates and entered my first logs but I'm having issues with the output. The log previews (both on output and via graphical input) look as they should but as soon as I actually export it for some reason it overrides all the Times New Roman text in the report with Arial meaning it all hangs over the lines as it is slightly larger. How do I fix this? As far as I am aware I haven't changed any font settings anywhere so am at a loss how to resolve this.

Thanks