Need advise on shrimp molting problem

[Leonhwr]

First of all i will start of with the specs of my setup.
64L 2 feet tank
ADA New soil
Eheim 2213 with original media
DW, Larva rocks, Mineral rocks from mosura.
US Fissiden, Mini Fissiden, Weeping Moss, Frog bits, mini lettuce.
Ammonia 0
Nitrite 0
Nitrate 0
pH 6.4-6.5
KH 2-3
GH 3-4

8 boraras brigatte, 4 Ottos, 3 Golden algae eater, 2 Panda cory and 2 Sterbai cory, 1 yamato, 3 bumble bee horned nerites.

Mainly Fire reds and had a few pieces of Chocolate shrimp in a breeder box. Have noticed that recently quite a few shrimps have died and seems to be molting problem. Cant exactly tell from the FRs as i have only noticed their drop in numbers but should be the same reason as the Chocolates. Chocolates that have died seemed to be unable to molt.

Can someone advise if this is the problem and what action should i take.
Thank you.

[Guppy77]

everything seems ok, do they only moult when you chnage water? also when you say they cannot moult, any shell left on the dead body?

[Leonhwr]

some molt fine. those FR i dont get to see anything left behind cus other have eaten them already. for the chocolates that died doesnt seem like they have any shell on some while other can tell from the under part of the shrimp can see like it had difficulty coming out of its molt. not really sure but looks like it.