A mother cat carrying her kittens to a new nest is a protective behavior, a sign of vigilance, and is very common after giving birth. After living in one place for a period of time, a cat will always leave behind some scent, which is dangerous in the wild. Therefore, even if there is no obvious disturbance, the mother cat will try to change locations; this is a mother cat's instinct. 
During the period immediately after a mother cat gives birth, we should avoid holding the kittens. Sometimes, the strong scent of humans can cause the mother cat to reject the kitten. Give them their own space as much as possible and prevent other animals in the house from approaching them, especially male cats, as mother cats are quite sensitive.
Although you feel safe at home, the mother cat may not realize this and will instinctively seek a safer place, a sign of strong maternal instinct. To alleviate the mother cat's anxiety, try thoroughly cleaning her original nest and removing as much odor as possible. It's recommended to build her and her kittens a new nest at home, ideally with some shade and light-blocking features, which will provide them with a greater sense of security.
This is genetically programmed in the wild. When a cat gives birth, she usually moves her litter 3-4 times to avoid being discovered by other animals. The litter is the best hiding place, and then the kittens are gradually moved to areas with more food. During this time, the kittens are taught survival skills. After 2-3 months, when the kittens are capable of hunting and surviving, the mother cat will drive them away to live independently, as survival itself is very difficult. It's not that she doesn't love her kittens.
