This issue happen on from v9.0 final
Step:
1. Create 20 user defined commands
2. Add 5 commands into Context Menu with Display name or not
3. restart MC
4. Open User Defined Commands and duplicate more 5 command from command no 2, 4, 6, 8, 16
5. Name new name for duplicated command.
6. Delete some commands are assign into Context Menu.
7. Open Context Menu and select item then "Command Display Name" and "Custom Display Name" is difference. If user does not set Custom Display then name from TreeView also difference Command Display