The latest patch has been released and is available from the support download center.
13.3.0 Generic Patch #13. Reference TEC605767
There is one specific note in the README file or on the TEC article for the following bug fix:
CLRT-77534: PRSUBMITTEDBY does not get updated when timesheet gets submitted via XOG (TEC1984436)
With the fix for this issue, we are now supporting user name in submittedBy attribute of timesheet submit XOG request. Please take care of any scripts which were using the ID value in submittedBy attribute.