https://systemadministratorsys.blogspot.com/2017/07/how-to-make-your-user-and-sysadmin-to.html
Suggested you enable those standard grants for fnd_concurrent_requests and create a new role and then assign to your USER and SYSADMIN. Please check below steps for details.
Using the Functional Developer Responsibility, type Code as "FND_CONCURRENT_REQUESTS"
1. End_dating the following grants
DEFAULT_ACCESS_VIEWREQ
ECO Implementation Concurrent Request Grant
XDO Concurrent Request Security
IPM System Administration Concurrent Requests Grant
2. Create a new roles and assign to your USER and SYSADMIN
1. As SYSADMIN user with “Functional Developer” responsibility, update object "Concurrent Requests".
Search for object Concurrent Requests.
Click on Concurrent Requests.
Click on Object Instance Sets tab.
Click on Create Instance Set button.
Enter Name, Code and Description for new instance set.
- Enter the following for predicate:
1=1
2.As the SYSADMIN user with “User Management”, go to Roles and Role Inheritance tab.
Click Create Role button
Input value for the following column
Application,Role Code.Display Name,Description
Click Apply button
then query the role you created just now,,click update icon.
click Create Grant button,Input value for the following column
Name,Description
For the Data Security Object enter “Concurrent Requests”.
Click Next and provide the Data Content Type of “Instance Set”.
for Instance Set choose instance set created in step #1
Click Next
The permission Set is “Request Operations”.
Click next and finish button
3. As the SYSADMIN user with “User Management”, go to Users
Under Search region,query user name your USER
click update icon,click Assign Roles button
Query the role which you created in step 2
click apply
Same steps for user SYSADMIN
4.Wait some mins (10-15mins) to make workflow Angent listener to proceed it
then retest your issue.