Hi Soumya,
Please paste the results from
dbmcli -d <DB-name> -u control,<password for control>
Share the length of password for control user?
Additionally as you performed system copy please refer to below SAP notes to adjust the password of DBM and DBA users.
Note 25591 - Password change for DBM and DBA users
Note 39439 - XUSER entries for SAP DB and MaxDB
Hope this helps.
Regards,
Deepak Kori