The status of the return cannot be changed manually in Tax Manager as the options do not appear. Change the rights for status's.
Check the user has the correct rights as required below:
Open Process Engine Console.
Select Default Tax Process or the Tax Process set up by your organisation as default.
Click on Edit Mode.
Click on Steps and select your needed Step.
To give rights, bring the user's name from Available Teams/Users to Assigned Teams/Users by clicking on the bottom arrow <.
To remove rights for a particular step, bring the user's name from Assigned Teams/Users to Available Teams/Users by clicking on the top arrow >.
Click Edit Mode and click Refresh.
The user will need to exit out of APS and open Tax Manager to refresh.