Have you applied any fertiliser to any of the trees recently? Is there any particular reason you can think of why these two are not growing? It would be great if you could take some photos of the trees that are growing and not growing so our members have a better idea of what might be going on.
You could apply a general-purpose fertiliser like Dynamic lifter and see if the plants respond at al to that.
More information will help our members give some great advice on whether the trees need fertiliser or are stressed and need other remedies.