Rbta question

One of my RBTAs is deflated and the other is not. The other RBTA is right next to the other. And about 2" higher than the other. I haven't changed much. My parameters are normal. I turned up my lights about 5% and one of the two was deflated when I came home from work. I fed them yesterday and did a 25 gallon water change. I did take my salinity up from 1.025-1.026. I wanted to see what it would do. It looks like just one of them is ticked off. You would think both of them would be deflated if there was an issue. I added a new frogspawn on Saturday. I am kind of stumped. Do nems just deflate? Is it trying to poop? I think it may be constipated... It did this the last time I fed it a little more mysis than normal. I am really contemplating just a couple small feedings a month. Once a week or every other week might be a little much