### Godot version

4.0.2.stable.mono

### System information

Windows 10 - 4.0.2.stable.mono - Any Renderer

### Issue description

In a script with an `@export` variable (with a non-default value), Godot will replace the first variable in the category with the same name. For example, if you're exporting a variable called "Vector", and the value is set to a non-default value, the first variable in the category called "Vector" will also be changed to the same value.

### Steps to reproduce

Attach said script to a node:
```
extends Node

@export var Vector: Vector2
@export_category("Vector")
@export var Var2: float = 1

func _process(delta):
	print(Var2)
```
When changing the value of the `Vector` export variable, the variable Var2 will contain the same value. This does not happen when the `@export_category` has a different name.

### Minimal reproduction project

N/A
struct PatternNode;
	struct PreloadNode;
	struct ReturnNode;
	struct SelfNode;
	struct SignalNode;
	struct SubscriptNode;
	struct SuiteNode;
	struct TernaryOpNode;
	struct TypeNode;
	struct TypeTestNode;
	struct UnaryOpNode;
	struct VariableNode;
	struct WhileNode;
	class DataType {
	private:
		
		DataType *container_element_type = nullptr;
	public:
		enum Kind {
			BUILTIN,
			NATIVE,
			SCRIPT,
			CLASS, 
			ENUM, 
			VARIANT, 
			RESOLVING, 
			UNRESOLVED,
		};
		Kind kind = UNRESOLVED;
		enum TypeSource {