Orchestrator is getting logged off when multiple users are trying to connect

Currently we are in process of upgrading uipath from 2017 to uipath2018 and testing is going and we have noticed that, 2018 Ui Path orchestrator is getting logged off when multiple users are trying to connect on the same tenant.

When 2 people logged in same time , try clicking on different link… one of the person suddenly logged.

Any one faced similar issue or any suggestions.