Haddoni On the Move

[Pastey]

Upon initial placement, my haddoni has not moved. For some reason, yesterday, after zero changes to lighting or flow, it decided to move so that it is partially covered by a rock. Obviously something has upset it but I'm a little lost as to what it could be or where to start "looking". Ideas?

For the record, no signs of illness that I could tell (gaping mouth/detachment/deflation).