Thank you all for your input. I don't know what variety they are - both plants came labelled as simply 'ficus lyrata'.
I don't compost the coffee grounds, banana peels etc anymore as I moved to an apartment with no garden or compost bins...so it's all fresh, but the plants are grown in store-bought potting soil, which probably has goodness knows what added in (but I don't usually subscribe to adding additional chemicals to plants). Maybe it is deficient in some minerals. I will have a look at possibly using a plant food and see if it helps.
Fiddle leaf 1 is too young and not tall enough to have his top lopped off I think. I just want the leaves to open out and look how I expected it to but a you say, it just might never happen due to the cultivar.
