Cannot resolve path to router correctly when call getting a single project API by encoded-path

my url is "https://47.103.68.133/gitlab/api/v4/projects/test%2Ftest?private_token=xxx" and the response is {"error": "404 Not Found"}

the expected response should be {"error": "404 Project Not Found"} or detail of this project

the outcome is all right when I call other gitlab API like listing all projects

/var/log/gitlab/gitlab-rails/api_json.log shows that： {"time":"2019-07-01T07:49:42.038Z","severity":"INFO","duration":0.59,"db":0,"view":0.59,"status":404,"method":"GET","path":"/gitlab/api/v4/projects/test/test","params":[{"key":"private_token","value":"[FILTERED]"}],"host":"47.103.68.133","ip":"58.246.36.50, 172.17.0.1, 58.246.36.50","ua":"PostmanRuntime/7.15.0","route":"/api/:version/*path","queue_duration":4.81,"gitaly_calls":0,"gitaly_duration":0,"correlation_id":"828SMnpSYx9"}