GraphQL Query only partially encoded

Hi all,

I'm having a weird issue when trying GraphQL query in my AEM application. In my query I want to filter with the brand which is a tag field. The URL according to AEM documentation need to be encoded:

But when I encoded the url like this, it just return no item.

localhost:4502/graphql/execute.json/contentfragment/get-central-content-list%3Busecase%3Dmyhighlights%3Bbrand%3Dauto%3Acaas%2Fmetadata%2Fbrand%2Fbmw 

When I only remove the encoding from the brand filter, then it works: 

localhost:4502/graphql/execute.json/contentfragment/get-central-content-list%3Busecase%3Dmyhighlights%3Bbrand%3Dauto:caas/metadata/brand/bmw

I wonder why graphQl behaves like that, should the parameter value not be encoded? I'm using AEM 6.5

Thank you