We've bought a kumquat plant last year with fruit already on it. This year it fruited again, but it is leaking sugary sap everywhere. There are big drops of sap on the fruit, but the whole plant and surrounding area is covered in it. The plant is in full sunlight in the conservatory. It didn't do this last year, so just wondering what is causing it? The instruction label said to not overwater it, and I did repot it last autumn with a gritty soil mix so that it drained easily. Any help much appreciated.