I’ve just been sidetracked looking at your lovely villa! You do seem to have the same mobile menu problem as Peter. Plus you don’t have galleries or testimonials working. Oh dear, just looked at Peter’s website and they aren’t working there too although strangely I did see a testimonial first click and then it was gone when I clicked back. 🙁
I don’t understand it. I have the old course website and all my plugins and theme are up to date and I don’t have these problems. (Fingers crossed.)
It does seem a coincidence that we did all have similar problems caused by speed booster pack for a while. As you have it turned off I cannot see how that is causing your problems now unless caching is still somehow holding onto the trouble maker. You could disable the caching plugin just in case (I disabled mine ages ago)?
Apart from that, I’m wondering about other differences between our sites. Do you have any extra plugins that you’ve installed since you created the site? I updated the php code to a recommended level a while back but I’d be surprised if everyone else (who aren’t having the problem) did that too.