Bring in potted lemon plant indoors before any damage or loss of fruit from cold weather.

Question

I have noticed that the leaves and fruit can’t accept the change.

Answer 1

Any change in environment will shock the tree. Try to provide ample light, adding a grow light if needed, warmth, humidity, and consistent watering. The tree should perk up after it adjusts to the new surroundings.

https://www.gardeningknowhow.com/edible/fruits/lemons/growing-lemon-trees-containers.htm

https://www.gardeningknowhow.com/edible/fruits/lemons/lemon-tree-leaf-drop.htm

https://www.gardeningknowhow.com/edible/fruits/lemons/learn-about-fertilizer-for-a-lemon-tree.htm