QmlJSEditor: Quick Toolbar re-appears sometimes

Steps to reproduce:

• create/open Quick Application (I've used a simple one without ui.qml file)
• use Designer or Editor to add some other items

Ways to reproduce the re-appearance:
Easiest way:

• have some unsaved changes
• place cursor at an item that has a QuickToolbar (e.g. Text), wait for the light bulb to come up, click on the light bulb to bring up the toolbar
• place the cursor outside of the current item (into another one, the surrounding item, or whatever)
• trigger a "Save" of the current file

Current result:

• Quick Toolbar re-appears

Second way:

• place cursor at an item that has a QuickToolbar (e.g. Text), wait for the light bulb to come up, click on the light bulb to bring up the toolbar (keep in mind on which item you've triggered the Quick Toolbar)
• place the cursor outside of the current item (into another one, the surrounding item, or whatever)
• switch to Design mode
• on the left inside the Navigator select the item you had triggered the Quick Toolbar on
• change at least one property of this item inside the Property editor on the right
• switch back to Edit mode

Current result:

• Quick Toolbar re-appears