Group Modify Power vs Needed Group Modify Power -- Irregularity

[Kharay]

The situation (summarizing the issue):

Group A:

...
Group Modify Power - 60
Group Member Add Power - 60
Group Member Remove Power - 60
...

Group B:

...
Needed Group Modify Power - 60
Needed Group Member Add Power - 60
Needed Group Member Remove Power - 60
...

Expected behaviour:

- Adding members to Group B
- Removing members from Group B
- Modifying Group B

Actual behaviour:

- Adding members to Group B - Working as expected.
- Removing members from Group B - Working as expected.
- Modifying Group B - NOT working.

Question: What are the possible causes for this? Please list them so I may address them one by one in hopes of resolving the issue. Privately hosted, by the way.

[SilentStorm]

Also need Permission Modify Power I think.

[Kharay]

Tested and tried and as expected, it makes no difference. All I want to accomplish is for Group A to be able to manage the icon for Group B, of which there are quite a few on the TS server in question.

Obviously, Manage Icons is also activated for Group A. But still, it will not let Group A modify Group B.

[SilentStorm]

i_permission_modify_power >= 1
i_group_modify_power >= i_group_needed_modify_power of the group(s) the user should be able to change
Grant Value for i_icon_id >= 1 (to change the Icon)