I would do a thorough cleaning over the next two weeks, one week tank, then next week filters.
Then I would use treated water not boiled, feel free to heat but not boil. Then don't do a water change for maybe three weeks, this will give the shrimp some serious time for making babies. Although still test the water and do a water change if needed.
On the boiling water thing, I am not a fan. Reason being...there was a study done for garden seeds and plants and different types of water were used to water the plants, like boiled water, distilled, city water and bottled water. Though I don't remember all that much about it, it did end up with the result that the distilled, almost no growth and boiled, very little growth, water did not grow the plants as well as the other water.
Also the TDS could be high, do you happen to have a meter or can you take two samples in to the lfs one of your tap water and one of your tank and ask for them to test the water to see if there is any difference? When you boil the water, you are condensing down the water and solids as the steamed water evaporates.
Nothing is glaring out to me, other than that boiled water, which could be a non-issue. I might see if you can obtain another handful of shrimp to add to your stock from a different source than what you already have. Maybe you need some new blood. That is what I would try.
Wishing you many happy shrimp babies.