Check if the SPN is already registered:
setspn -l domain\xxxxx
If not, run below commands:
setspn -A MSSQLSvc/abc.xx.companyname.com:1433 domain\xxxxx
setspn -A MSSQLSvc/abc.xx.companyname.com domain\xxxxx
setspn -A MSSQLSvc/abc:1433 domain\xxxxx
setspn -A MSSQLSvc/ abc domain\xxxxx
Verify again,
setspn -l domain\xxxxx