Hi Gina, thank you that's interesting. I'll segregate the plant in case it's mosaic virus for the time being and have a look for some suitable fertiliser.
Whilst it is generally newer leaves displaying this discolouration on the adansonii, the three newest leaves (pictured) do actually look generally healthy. There are still new shoots growing. So I'm praying it's not mosaic virus!
Thanks everyone for your help :)