They do prefer a slightly lower than average ph, and warm water. You haven't said much about the tank or your water quality... Do they have places to hide? Is there ammonia in your water? High nitrates? Do you have adequate flow and aeration?
Not sure about the ph (lost the color card). I don't think nitrates coiuld be the problem as I tried a 45% water change and it did not help at all. I do have adequate flow, I do not use an airstone (planted tank with diy co2) but none of the fish are showing any signs that would indicate lack of oxygen. There are many places to hide.
I am currently acclimating the Bamboo shrimp to my now vacant (except for pond snails) 2.5 gallon tank which I have been keeping cycled (I will also keep a close eye on water parameters, just to be safe). The 2.5 gallon tank has hiding places and two filters (both running) so hiding places and flow will not be problems. If it was my Betta then my Bamboo shrimp should start acting normal soon due to me moving him into a tank other than the tank that has my Betta.
I am waiting on adding the cup of aquarium salt per 5 gallons to see if being away from Emerald helps. But I did add a half of a table spoon of aquarium salt (the recommended dose), just to see if it helped.