Double URL encoding in https://app.apiary.io

[Kreijstal]

I'm using python flask rest jsonapi and the API looks something like this

it is using %5b and %5d because [ and ] are not allowed,

however when I want to run the example on the website it double-encodes it again into %255b and %255d urlencoding the % sign, which of course results in a bug. The naming notation comes from python flask framework, so is there anything I can do in this special case?