WRONG!!!
As with all aquatic invertebrates it is important to make sure copper does not get into the aquarium. Copper is toxic to all Dwarf Shrimp. Many medications and fertilizers contain elevated levels of copper, so it is recommended not to medicate or fertilize an aquarium with Dwarf Shrimp in it.
Secondly, Red Cherry Shrimp (RCS) prefer PH levels between 6.5 and 7.6. They can survive in 6.0 - 8.0 but will not likely breed successfully above 7.6. Your water is just a wee bit hard I am guessing. Try lowering your PH, make sure you are not adding copper in any form and go from there.