ID 9566 - Projectors palette "Sorted by" combobox does not display correctly

Problem summary
Projectors Palette Sorted By dropdown menu not visible

Customer reported version
Mari n/a

Customer reported platform
n/a

Steps to reproduce

1) Open an Example Project

2) Open the Projectors Palette (View > Palettes > Projectors)

3) Create a new projector

Expected behaviour
A dropdown menu for different sorting options should be visible at the top of the Projectors Palette

Actual behaviour
The dropdown menu is not visible

Workaround
If Projector items are present when the project is loaded, the sorting menu is visible. Therefore, once Projectors have been added, closing and then reopening the project will reveal the dropdown box.

Reproduced by support
This bug has been reproduced in:
Mari 4.7v2 - Windows 10 - CentOS 7.7
Mari 4.7v1 - Windows 10
Mari 4.6v1 - Windows 10
Mari 4.5v1 - Windows 10
Mari 4.0v1 - Windows 10
Mari 3.0v1 - Windows 10 - CentOS 7.7

Earliest version tested
Mari 3.0v1 - This issue appears to be in all versions of the product