Can not add new group in Tab and Notebook layout pages

### Current Behavior

Added page to layout using Grid Layout.
Then added three groups and filled them.
Decided to use Tabs Layout and changed the page.
As expected new tapped layout is displayed.
Wanted to add another group to that page, but the + Add Group button in that page Line is not shown.
Changed page back to Grid Layout. Button appears and new group can be added.
Assigned a button to the new group.
Changed page to Tabs layout.
New Tab with the ne button is displayed.
The same behaviour happens when you use Notebook layout.

### Expected Behavior

Adding a group to a page should be possible in all 4 layout types.

### Steps To Reproduce

See current behavior.

### Environment

- Dashboard version: 1.20.0
- Node-RED version: 4.0.7
- Node.js version: v20.18.0
- npm version:
- Platform/OS: raspberry Pi Bookworm
- Browser: Firefox

### Have you provided an initial effort estimate for this issue?

I am not a FlowFuse team member