And someone else here also said that there was no problem with his ceramic coating (in a older thread).
Could be a couple things: It happened that the engine was painted with this stuff when ceramic paints had first come out many years ago, so it's possible that the formula had not been as good as it is today as it was in it's infancy. However, everything was ****-and-span applied at the proper temperature and had been heated by the engine under normal operating temperature for a couple years prior to the first cleaning.
Oil was present on the surface at the time I attempted to clean off the surface with a soft cloth soaked in gasoline. Perhaps the oil broke down the paint over time. Yet there were other areas that had some road grime (such as the oil pan) that I also wiped off with the gas cloth and it wiped the paint right off down to bare metal there also.
Nowadays, I am using enamel, but it is hard to find, especially in the Ford red/orange color, but every once in a while I run across a can and I pick it up if I am running low on the stuff.