Sorry to hear you have lost half the remaining shrimps. At least you have another taiwan bee tank which is doing fine. Be careful not to take anything (including shrimp) from the bad tank and put it in the good tank! It could be an infection as LukeBeveridge above, maybe some shrimp were sick when you got them.
Time to start thinking/preparing to start that tank again! If you are using something different in the tank that you aren't using in any other tank then use what has worked well with the other tanks. At least there is no rush so you can do it at your leisure, and once it is up and running you should have shrimplets you can transfer from your other tank!
There is a device out there to prevent heaters overheating by cutting the power to the heater when it gets too hot, it probably would be worth getting one of those, at least for the taiwan bee tank(s).
The parameters look fine. The nitrate figue may indicate the tank isn't cycled properly, but I have a tank that has nitrate 25 permanenetly for 5+ years with no problems. You could test the nitrates in the other taiwan bee tank and see what they are out of curiosity, but as I assume you will be re-setting up the bad tank it probably may be better to just get ready to do that.
I feel your disappointment have a tank that is exactly the same and I have (temporarily) given up on that (as I don't know what the problem is) and just have fish in it for now, but I would have to start again if I want to start with taiwan bee shrimp again......
Yes the "camo" shirmp as ive been calling it is about 1/3 of the size of the yellow shrimp the other green shrimp which where all males where about 1/2 the size of the yellow shrimp. Thats why im leaning toward this being the offspring of the yellow and green and being a pure hybrid of the two. Who knows tho. The color morph theory is convincing as well but the size of this shrimp makes me wanna believe its a hybrid.