Not possible to perform variable mapping with the variables with the same name

Issue

There is a process created in 6.0.1 that have a process variable named "incidentVO". In many of workitemhandlers the expected parameter is named "incidentVO".

This was fine in the previous version and the defined mapping was the following:
From process variable to data input as incidentVO -> incidentVO

With the upgrade to 6.0.2 / 6.0.3 this mapping is marked as invalid. Specifically it is not possible to create new mappings like this - where FROM and TO variables have the same name. When trying to create an assignment, there is a pop-up warning box with following message, and the warning box disappears very soon with no error logs in server.log.

Assignment for ${VAR_NAME} is invalid.

The kjar created with these processes still loads fine, and the processes still execute fine with the 6.0.2 / 6.0.3 version. This issue is only affecting the designer.