"Allow Empty Value" only works before you select then unselect something from the array list

[tthornton3-chwy]

Q&A (please complete the following information)

• OS: ALL
• Browser: ALL
• Version: ALL
• Method of installation: ALL
• Swagger-UI version:Latest/5.32.8
• Swagger/OpenAPI version: Swagger 2 OpenAPI 3.1

Content & configuration

Allow empty only works once. If you select something from the list, and unselect, the empty query parameter does not get attached.

Example Swagger/OpenAPI definition:

{
                        "name": "status",
                        "in": "query",
                        "description": "Find Something. Send status= to clear the status filter.",
                        "style": "form",
                        "explode": true,
                        "allowEmptyValue": true,
                        "schema": {
                            "anyOf": [
                                {
                                    "type": "array",
                                    "items": {
                                        "type": "string",
                                        "description": "Something",
                                        "enum": [
                                            "FOO",
                                            "BAR"
                                        ]
                                    }
                                },
                                {
                                    "type": "null"
                                }
                                
                            ]
                        }
                    },

Swagger-UI configuration options:
Defaults.

To reproduce...

Steps to reproduce the behavior:

1. Have an api-doc similar/including to what I shared above.
2. Check the "Allow Empty" checkbox
3. Send a request and see that it works / status= is sent.
4. Select then unselect any item in the list. It should be empty again.
5. See that status= is NOT sent.

Expected behavior

status= should continue to be sent after selecting/unselecting everything.

Screenshots

Additional context or thoughts

I have already fixed this here: #10940 :)