Hi Robyn,
Can you put a break point in the method - DO_HANDLE_DATA of the view controller super class and check if the values which you are providing in the UI and traced back or not.
It's really a very strange behavior that in one transaction type the AET Code generation is working correctly while in the other it is imposing so many restrictions. Is there are any SAP Note in the SOL Man system ?
Unfortunately I don't have a SOL MAN system and can share you any code from a CRM System only. Let me know if you need any help in terms of technical input.
Hope this helps.
Best Regards,
Samantak.