While setting up the Xero connector I faced an issue when after 30 minutes connector stopped working and return an error 400:

Type=Microsoft.DataTransfer.Common.Shared.HybridDeliveryException,Message=ERROR [HY000] [Microsoft][Xero] (61) API Connection Failed. Bad Request. HTTP Response code: 400\r\nERROR [HY000] [Microsoft][Xero] (61) API Connection Failed. Bad Request. HTTP Response code: 400,Source=Microsoft.DataTransfer.Runtime.GenericOdbcConnectors,''Type=System.Data.Odbc.OdbcException,Message=ERROR [HY000] [Microsoft][Xero] (61) API Connection Failed. Bad Request. HTTP Response code: 400\r\nERROR [HY000] [Microsoft][Xero] (61) API Connection Failed. Bad Request. HTTP Response code: 400,Source=,'",