Shrimp identification.

About a year ago I bought a handful of 'cherry shrimp' from an auction site as food/tank cleaners for my axies. I read about them and chose cherry's because they are supposed to breed real fast and are easy to keep.
The thing is, for a couple of months, I'm thinking that the shrimp I have are not cherries at all.
They are not red, but transparent. Sometimes I see a little bit of red, but nothing noteworthy.
According to some sites on internet they should be around 3cm long, and mine are about 1-2cm. (excluding antennae).
Cherry's are supposed to breed like crazy, but these ones are not breeding fast at all. They breed, but very slow. When I brought them home, I had a pregnant female in the batch that was filled with black eggs. I read that cherry's have yellow/green eggs.

It can be that my shrimp are kept under wrong conditions and they are not happy, so I'm not sure about the species.

I'll try to get some pictures tomorrow, but I don't know If I can manage, since they are so small and transparent.

They are kept in a tank of about 25l and on sand. I only have about 15, so the tank should be big enough.

They are Red Cherry. They color fade when they are stressed, and some are more colorful than others. "Breeding like crazy" is not sure in every tank, and you have them with axolotls as food.

They are in a separate breeding tank, so they have all the peace to breed.
I was planning to introduce them to the axie tank when I have a lot of shrimp, so I don't influence the population too much.

What can I do to lift the stress?

More plants (especially mosses), more hiding places and more food for them - think it should help.

More plants (especially mosses), more other hiding places and more food

They only need algae, right? There is more thread-algae in the tank than these guys can eat at the moment.