Plumeria

I have two Plumeria Pua Malia that I have grown from seeds that I brought back from Oahu when I visited the Hawiian Islands two years ago,they have both grown with no problems but now the leaves have lost their shine and have become mottled.

When I re-potted them the last time I used ericacuos compost thinking that this would cure it but to no avail.

Any ideas?

Jeff.