swagger-codegen-maven-plugin overwrites files even when listed on .swagger-codegen-ignore

Issue is raised with Java when using: io.swagger.codegen.v3:swagger-codegen-maven-plugin:3.0.21 when building with gradle.
The content of the .swagger-codegen-ignore is:
**/DocumentApi.java
I'm adding the swagger ignore file location in gradle generateServer task

task generateServer {
    doLast {

        def openAPI = new OpenAPIV3Parser().read(swaggerFile, null, null)
        def clientOpts = new ClientOptInput().openAPI(openAPI)
        def codegenConfig = CodegenConfigLoader.forName('spring')
        codegenConfig.setIgnoreFilePathOverride("$projectDir".toString()+"/src/main/resources/static/.swagger-codegen-ignore")
       

however, the file DocumentApi.java is regenerated and the old configuration is not preserved.

Can you please tell me how to avoid the regeneration of a specific API or how I can exclude in the configuration that an api definition to be created for a specific endpoint?

Reproduce the report using swagger-codegen-maven-plugin 3.0.21, the shown Gradle generateServer task, and a .swagger-codegen-ignore entry for **/DocumentApi.java. Trace how CodegenConfigLoader and setIgnoreFilePathOverride handle that file, then verify that generation preserves the existing DocumentApi.java content while other generated files still work.