[Wayland] Some text fields don't get edited on window popup

### Tested versions

4.8 dev eda2a48

### System information

openSUSE

### Issue description

When you try to connect to a signal, the connection dialog opens and the method name field gets selected, but there is no caret and it can't be edited immediately.

You need to click it to edit.

This doesn't seem to affect all dialogs (for example CreateDialog works correctly). Also does not happen on X11.

### Steps to reproduce

1. Add any node
2. In Signals dock, double-click any signal
3. Try typing anything in the selected method name field

### Minimal reproduction project (MRP)

N/A

Reproduce on openSUSE under Wayland using the listed steps, then compare the signal connection dialog with CreateDialog and the same flow on X11. Trace how the selected method name field receives focus when the dialog opens. Done means the field can be edited immediately without an extra click, while existing dialogs remain unaffected.

Written by the indexing model from the issue text.