Ruby Net:HTTP::Get weird behavior with JSON

Question

I am using Net::HTTP for sending GET request to an API Server to fetch some data based on some configurations as below:

# method to fetch shirt sample details from api server
def fetch_shirt_sample(shirt, query_params)
  path = "http://myapiserver.com/shirts/#{shirt.id}/shirt_sample"
  url = URI.parse(path)
  req = Net::HTTP::Get.new(url.path + '?' + query_params)
  res = Net::HTTP.start(url.host, url.port) { |http| http.request(req) }
  JSON.parse(res.body)
end

What is wrong or weird I found is above method works for following query params:

"&name=medium_shirt&color=red&configs=[\"full_length\",\"no_collar\",\"casual\"]"

but doesn't even send GET request for following query params:

"&name=medium_shirt&color=red&configs=[\"full_length\",\"15\",\"43\",\"30\"]"

Could anyone help me to understand what is wrong in the above setup?