If the spikes are sticking through deflated tissue, the acan is in defensive mode for some reason. This is common when new specimens are added to the tank and they acclimate. If it stays this way it could be that conditions not suitable for it (light, flow etc). Acan L should be puffy most of the time. Some A. LordH are moody corals and fussy about having just the right location. A pic with detailed info of its immediate environment would help.