Receiving 503 Service Unavailable on some endpoints in Sandbox mode

Some endpoints of the API return 503 Service Unavailable such as the endspoints to sync call logs, retreive call logs, sync messages and retreive messages. The endpoints to retreive account information and user information however are working fine and also the calls to subscribe to pubnub events works too.

Here's an exemple of a call to access call logs:

1. 
   
   1. 
      
      1. 
         
         1. Request URL:
            https://platform.devtest.ringcentral.com/restapi/v1.0/account/~/extension/~/call-log
         2. Request Method:
            GET
         3. Status Code:
            503 Service Unavailable
         4. Remote Address:
            192.209.29.78:443
         5. Referrer Policy:
            no-referrer-when-downgrade
      2. Response Headers
      3. 
         
         1. Access-Control-Allow-Credentials:
            true
         2. Access-Control-Allow-Origin:
            http://jurisconcept.ca
         3. Access-Control-Expose-Headers:
            Date, RoutingKey, Content-Length, Content-Encoding, Retry-After, RCRequestId, X-Rate-Limit-Group, X-Rate-Limit-Limit, X-Rate-Limit-Remaining, X-Rate-Limit-Window, ETag
         4. Connection:
            keep-alive
         5. Content-Language:
            en-US
         6. Content-Length:
            177
         7. Content-Type:
            application/json;charset=UTF-8
         8. Date:
            Mon, 18 Feb 2019 21:58:24 GMT
         9. RCRequestId:
            5018112c-33c8-11e9-9ec0-005056bb26b9
         10. Retry-After:
             40
         11. RoutingKey:
             SJC12P01PAS02
         12. Server:
             nginx
         13. X-Rate-Limit-Group:
             heavy
         14. X-Rate-Limit-Limit:
             10
         15. X-Rate-Limit-Remaining:
             9
         16. X-Rate-Limit-Window:
             60
      4. Request Headers
      5. 
         
         1. Provisional headers are shown
         2. Accept:
            application/json
         3. Authorization:
            bearer U0pDMTJQMDFQQVMwMHxBQUJGYVVZcmlhNVpzYkhsSTlEUVVCT3JZVEpremd4ellvNjV6T3UyWEhna2liaFFYTE81Y0RnT1RGV0pTSWY3TmdoNF9QWWRPMEVYNENYQjd4dmJsWHJoTzZKcVBrRTlVdzA4RWFEc3FFZ0lVRlhOelg4cDZ3OFhVVlhwbDgwMVVILXlXaEpqdGpIXzF1aDNNYnZsTHRHd1QzbkNNOXdLNl9OeTd2U25rWDM3aXJTcHI0QkhicExuZDg1M3NDeFZ2Z2F1VzUwLUViUEZhTXpDUkp0eWUtRTR8ZWpnRjNnfG1CRndkX1d3RlVKODJUVy1rRUNPTGd8QUE
         4. Client-Id:
            kG8uXDKbRfG_QyRcdid1LQ
         5. Content-Type:
            application/json
         6. Origin:
            http://jurisconcept.ca
         7. Referer:
            http://jurisconcept.ca/app/
         8. User-Agent:
            Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/72.0.3626.109 Safari/537.36
         9. X-User-Agent:
            RCJSSDK/3.2.1