Custom controls not visible on iOS

mapbox-gl-js version: 1.9.1
mapbox-gl-draw version: 1.2.0-dev (https://github.com/trygveaa/mapbox-gl-draw/tree/dont-drag-with-multiple-fingers)

Steps to Trigger Behavior

1. Ionic 5 (Angular) Application with mapbox-gl-js and mapbox-gl-draw

new MapboxDraw({
    displayControlsDefault: false,
    controls: {
        polygon: true,
        trash: true
    }
})

Expected Behavior

Custom draw controls are visible on all platforms

Actual Behavior

Custom draw controls are not visible on iOS. Using the default draw controls (new MapboxDraw()) is working.
However, the custom draw controls are visible on macOS in Chrome and Safari.

iOS 13.4 (iPad 6. Generation)

Custom draw controls	Default draw controls

macOS Chrome

Custom draw controls	Default draw controls
	is also working

The weird thing is that the draw controls are visible when I pan the map and tiles have not been loaded yet. When the tiles load, they are on top of the controls. Changing z-index on the controls doesn't have an effect however.

Start by reproducing the issue with the MapboxDraw configuration shown in an Ionic 5 Angular application on iOS 13.4, then compare custom and default controls while map tiles load. Done means custom draw controls remain visible on iOS after the tiles load, without relying on z-index changes.