QComboBox Item list opened with wrong position and background after changing keyboard layout on Split view portrait mode

Preconditions:

Application includes

• QMainWindow with QComboBox OR
• maximized QDialog with QComboBox.
  Application is on portrait mode.
  Split view is open with qwerty or alphanumeric keyboard.

Test steps:
1. Change the virtual keyboard layout (from qwerty to aplphanumeric or vice versa, or between aplhanumeric alpha-number layouts).
2. Open the QComboBox item list from small arrow icon (on QComboBox).

Expected result:
Item list is visible at the bottom of the screen.

Actual result:
Item list is drawn at the upper part of the screen.
Background application is visible between the item list and control pane.
If the item list is opened again, it's correctly displayed.