Academic Knowledge Cognitive Services Labs API error 500

I have obtained API keys for the Cognitive Services Labs by Microsoft here, but when I try using the example provided in the API "Try me" page for the graphSearch method, I get a 500 server error after about 20 seconds. Other API endpoints (interpret, evaluate) seem to be working well. Here's my query (also tried via the "Try me" page):

export SERVER=api.labs.cognitive.microsoft.com

curl "https://${SERVER}/academic/v1.0/graph/search?mode=json" \
    -H "Host: ${SERVER}" \
    -H 'Content-Type: application/json' \
    -H "Ocp-Apim-Subscription-Key: ${API_KEY}" \
    --data '{"path":"/paper/AuthorIDs/author","paper":{"type":"Paper","NormalizedTitle":"graph engine","select":["OriginalTitle"]},"author":{"return":{"type":"Author","Name":"bin shao"}}}'

I've written an inquiry via the Cognitive Services UserVoice portal but with no answer so far. The service is not listed in the Azure Status page.

I want to know whether my query or account registration is faulty, or is this a temporary problem. Should be easy to answer.