Created attachment 193893 [details]
Older screenshot with buttons

Description:
In KDE System Settings, the IPv6 configuration page for a wired connection no longer shows the controls needed to add or remove manual IPv6 addresses.

This happens in:

System Settings → Wi-Fi & Internet → Wi-Fi & Networking → Wired connection → IPv6

When the IPv6 method is set to Manual, the address table is visible, but the Add, Remove, and Routes... buttons are not visible anymore. This makes it impossible, or at least not discoverable, to add a manual IPv6 address through the GUI.

In an older version of the same dialog, these controls were displayed correctly on the right side of the IPv6 address table.

Steps to reproduce:

1. Open System Settings.
2. Go to Wi-Fi & Internet.
3. Open Wi-Fi & Networking.
4. Select an existing wired connection, for example Wired connection 1.
5. Open the IPv6 tab.
6. Set Method to Manual.
7. Try to add a manual IPv6 address.

Actual result:
The IPv6 address table is shown, but the Add, Remove, and Routes... buttons are not visible. The layout appears to overflow horizontally, and a horizontal scrollbar is shown at the bottom of the page. The controls that should allow adding or removing IPv6 addresses are missing from the visible UI.

Expected result:
The Add, Remove, and Routes... buttons should remain visible and usable in the IPv6 tab, as they were in the older version of the dialog. The user should be able to add, remove, and configure manual IPv6 addresses without needing hidden or off-screen controls.

Why this matters:
This is a functional regression in the GUI. Manual IPv6 configuration cannot be completed from System Settings because the button required to add an address is no longer accessible in the visible interface.

Additional information:
I attached two screenshots for comparison:

Older behavior: the IPv6 tab shows the address table together with the Add, Remove, and Routes... buttons.
Current behavior: the IPv6 tab shows the address table, but the buttons are no longer visible.

Both screenshots show the same general dialog and the same IPv6 page. The main difference is that the older UI exposes the manual address controls, while the current UI does not.