Custom Model does not work with QComboBox on Ios

When a custom model is set with QComboBox this does not shows the items in the drop down when deployed on ios device/simulator. 

When click on combobox you see drop down but items are not visible scrollable and selectable with "done" button as well. Though it does plays the sounds of item being scrolled. 

Output pane displays bunch of following messages

QPlatformInputContext::inputMethodAccepted() does not match actual focus object IM enablement!
QPlatformInputContext::inputMethodAccepted() does not match actual focus object IM enablement! 

This works with arrow key though.

Same works if the style is changed to windows. 

Attached is the example and screen recording (at the end of recording up/down keys are used)