Yes, water changes can trigger molting.
What has worked for me is to feed a vegetable/algae based diet twice a week (I use Ken's Fish veggie sticks - but actual veggies or other vegetable/algae based foods work too!) and a protein food once a week. (tend to vary this). It could be fish flakes, frozen food or something else. I have the Fluval food somewhere... and I don't feed it. When I did, I had yellow shrimp and it turned them green. It does make red shrimp redder at least.... however, that could pose an issue when you are trying to breed well colored shrimp and they aren't the 'right' color...
Many of the "algae pellets" are actually algae infused, not algae based...
I hoe you don't have any more losses and they recover.
Still not much of a change, sadly. I also lost one yesterday but the rest are still going. They're foraging in place for some reason so hopefully they're eating at least a little.
Did a 10% yesterday and another 10% today. I'll test the water once the drip is done.
The Shrimp King Complete came the other day. Two of the 3/4 that are moving around nibbled on it. Just picked up Sera Spirulina Tabs as well. Crumbled that into tiny pieces. It's been in for 5 minutes and one is already on it. 24% spirulina, 16% sea algae, 9% krill/fish meal, and some stinging nettle and alfalfa, spinach and carrots, all that stuff.
Took a vine of java moss out that wasn't doing too well. It was brown to begin with but I hoped it would turn green again. Some of it did so I think it's alive... Moved moss balls to where it was, including the one they've been hiding under. They're spread out more in the corner now and not stacked on top of each other. Hopefully that at least makes them move a tiny bit more. If they don't I'll drop food there instead of in the dish and just deal with sucking it up out of the sand. I'd rather them eat.
Edit/update: just checked the parameters. Ammonia is at 0!! Everything else is good too. I'll check again tomorrow or the day after, but maybe now they'll snap out of it.