I had a LTA act similarly and thought the foot was ok as well. Mouth open, not attaching, yeah. I took a closer look and saw a little raw area right in the middle of the “sole” of the foot. Mr. Nem went into cipro treatment for ten days. When I added it back to the tank, I dug a little pit, place a small rock at the bottom, put the nem on top of it and buried the thing in sand and left just the mouth exposed. A few hours later, I gently poofed the rest of the sand away with a turkey baster. That nem hasn’t moved, has doubled in size and I swear its mouth has never closed. He’s the one furthest to the right. I actually used that same placement technique for the other LTA and the Purple Sebae in the middle and they stayed exactly where I placed them.