Before going in to too much detail, can you confirm what you mean by 'used Orion SDK', are you referring to the SWQL Studio or some of the code samples?
A 401 error is an authentication issue, which as you have recreated this in elsewhere would indicate this is an account problem. You say LDAP, but I am presuming this is as part of the AD account integration
1. Review your account settings in Orion and confirm you can log in to Orions web interface. To interact with the API, the permissions level on your account will reflect what you are then allowed to action against the API
2. Try authenticating using an internal Orion user account to rule out account issues