UIDropDownMenu does not work with negative relative rect

[RocketRider]

I want my elements to be relative to the right border, so I am using negative positions:

self._anchors = {'left': 'right', 'right': 'right', 'top': 'top', 'bottom': 'top'}
self.request_cs_spinner = pygame_gui.elements.UIDropDownMenu(relative_rect=pygame.Rect((-275, 220), (200, 30)),
                                                                     options_list=["1", "2"], manager=self._ui_manager,
                                                                     anchors=self._anchors, starting_option="1")

This results in an empty box.

When I do the same with a "normal" position it works as expected:

        self.request_cs_spinner = pygame_gui.elements.UIDropDownMenu(relative_rect=pygame.Rect((275, 220), (200, 30)),
                                                                     options_list=["1", "2"], manager=self._ui_manager,
                                                                     anchors=self._anchors, starting_option="1")

With other elements, like buttons, it works as expected.

I tested it with 0.57, branch 'version_060' and the master. I am using pygame 2.0.0.

[RocketRider]

UIWindow seems to have the same issue

[MyreMylar]

I'll investigate this.