I had my pairs set up at my house, then moved them over to a retail location to allow for the expansion of my breeding, it took some pairs over half a year to spawn again and some didnt skip a spawn. My guess would be that they will spawn again, in given time. Being in a reef tank they might not have found the "right" spot yet, but when they do they should start spawning again. If you want to speed up the process then put them in a separate tank that is just them and a clay pot, you can plumb it to your reef tank, and the lack of distractions should allow them to spawn sooner.