Amano shrimp love meaty foods. They really do eat algae too, but in my early shrimp keeping, I was feeding barely any food to the tiny shrimp / shrimp only tank and just algae type foods.
Can't recall at the moment which bottom feeder fish I added but I gave it a Hikari Omnivore sinking wafer and the Amano basically jumped out, mid wafer fall and grabbed it and the other Amano were about at war /seriously aggressive in their behavior to get the meaty wafer.
So maybe they are hungry. They eat much more than the smaller shrimp.
Is there a intake cover on the filter?
Is the water parameters set to the Neos specific care needs? They can be more sensitive than average Cherries.
What are your water parameters
Do you top off water from evaporation with tap water (dechlorinated), or RO
How often are you doing water changes and how much?
I would move the Amanos shrimp to a tank with small mouthed nice fish.
As for babies, I would use some specialty shrimp food if you are trying to get the best colors.
That said, the 2 kinds of shrimp are both Neocaridina unless the Yellow is a yellow King Kong Caridina.
The Neocaridina are very pretty and when kept with their own variety (ie. Blue Velvet) color shrimp, they breed true where most all their babies are like them.
But when you have 2 different color groups you risk them having assorted color babies in the tan, grey, clear color groups and after a few rounds of breeding with the pale "colorless" shrimp they will mostly be pale and have little color.
You can grab a bag of Crab Cuisine appx $3.99 at many stores. It has minerals needed for molting and good shell growth.
Add a chunk of bird Cuttlebone also for minerals. Pure unflavored, it floats for an undetermined amount of time. Eventually will sink. Put the hard shell side to the air when floating - when it sinks just sit it behind a plant or rock, soft side up/out. They eat off the soft side.