### 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
return members[members_indices[p_name]];
		}
		bool has_member(const StringName &p_name) const {
			return members_indices.has(p_name);
		}
		bool has_function(const StringName &p_name) const {
			return has_member(p_name) && members[members_indices[p_name]].type == Member::FUNCTION;
		}
		template <class T>
		void add_member(T *p_member_node) {
			members_indices[p_member_node->identifier->name] = members.size();
			members.push_back(Member(p_member_node));
		}
		void add_member(const EnumNode::Value &p_enum_value) {
			members_indices[p_enum_value.identifier->name] = members.size();
			members.push_back(Member(p_enum_value));
		}
		void add_member_group(AnnotationNode *p_annotation_node) {
			members_indices[p_annotation_node->export_info.name] = members.size();
			members.push_back(Member(p_annotation_node));
		}
		ClassNode() {
			type = CLASS;
		}
	};
	struct ConstantNode : public AssignableNode {
#ifdef TOOLS_ENABLED
		String doc_description;
#endif 
		ConstantNode() {