SCCM upgrade from 1802 to 1906 error

I am trying to upgrade sccm server but it looks stuck.

Status :- [Completed with warning]:Monitoring database replication initialization. Check cmupdate.log and rcmctrl.log for details.

cmupdate.log :- Waiting for changes to the “C:Program FilesMicrosoft Configuration Managerinboxescmupdate.box” directories, updates will be polled in 600 seconds…

rcmctrol.log  :- Cleaning the RCM inbox if there are any *.RCM files for further change notifications…. SMS_REPLICATION_CONFIGURATION_MONITOR 5/28/2020 12:40:57 PM 79260 (0x1359C)
Rcm control is waiting for file change notification or timeout after 60 seconds. SMS_REPLICATION_CONFIGURATION_MONITOR 5/28/2020 12:40:57 PM 79260 (0x1359C)
Processing Replication success. SMS_REPLICATION_CONFIGURATION_MONITOR 5/28/2020 12:40:57 PM 51164 (0xC7DC)
Cleaning the RCM inbox if there are any *.RCM files for further change notifications…. SMS_REPLICATION_CONFIGURATION_MONITOR 5/28/2020 12:40:57 PM 79260 (0x1359C)
Rcm control is waiting for file change notification or timeout after 60 seconds. SMS_REPLICATION_CONFIGURATION_MONITOR 5/28/2020 12:40:57 PM 79260 (0x1359C)
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found below error:-

The asynchronous command finished with return message: [A .NET Framework error occurred during execution of user-defined routine or aggregate “spDRSActivation”: ~~Microsoft.ConfigurationManager.DataReplicationService.ServiceException: Exception has been thrown by the target of an invocation. —> System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. —> System.Data.SqlClient.SqlException: The conversation handle “032AD4E4-C6A0-EA11-910D-005056BB6EC5” is not found.~~System.Data.SqlClient.SqlException: ~~ at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction)~~ at System.Data.SqlClient.SqlInternalConnectionSmi.EventSink.DispatchMessages(Boolean ignoreNonFatalMessages)~~ at System.Data.SqlClient.SqlCommand.RunExecuteNonQuerySmi(Boolean sendToPipe)~~ at System.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(TaskCompletionSource`1 completion, String methodName, Boolean sendToPipe, Int32 timeout, Boolean& usedCache, Boolean asyncWrite, Boolean inRetry)~~ at System.Data.SqlClient.SqlCommand.ExecuteNonQuery()~~ at Microsoft.ConfigurationManager.DataReplicationService.Conversation.EndConversation(SqlConnection connection, SqlTransaction transaction)~~ at Microsoft.ConfigurationManager.DataReplicationService.MessageHandlerService.ProcessErrorMessage(Message msgReceived, SqlConnection connection, SqlTransaction transaction, Int32 logLevel, SqlCommand command)~~System.Reflection.TargetInvocationException: ~~ at Microsoft.ConfigurationManager.DataReplicationService.Service.Run(SqlConnection connection, SqlTransaction transaction, Int32 logLevel, SqlCommand command, Int64 poisonMessageSequenceNumber)~~Microsoft.ConfigurationManager.DataReplicationService.ServiceException: ~~ at Microsoft.ConfigurationManager.DataReplicationService.Service.Run(SqlConnection connection, SqlTransaction transaction, Int32 logLevel, SqlCommand command, Int64 poisonMessageSequenceNumber)~~ at Microsoft.ConfigurationManager.DataReplicationService.MessageHandlerSe…].