Hi there, thanks for having a look, we've managed to fix it in the last couple of days.
The code in the screenshot above is actually the raw code that the cache stores the website files as, and for some reason Google was seeing the file in that form.
We did have the cache system set to re-generate at midnight and that was interfering with when Google was indexing the site.
Have changed the cache re-generation to 2am and the problem with the results has gone away.