We have some problem trying to list Google Container Registry images via Docker Registry HTTP API V2

When executing this command:

curl -k -s -X GET "https://eu.gcr.io/v2/_catalog" -L -H 'Authorization: Bearer ${TOKEN}'

Sometimes we get an empty json {"repositories":[]} and sometimes we get the correct json with all the information {"repositories":["projectname/image1","projectname/image1"]}

Does Google Container Registry fully support Docker Registry HTTP API V2? Is anybody else experiencing this issue?