Code for the thing
let fileBrowser = UIDocumentPickerViewController(documentTypes: listOfAllTypesOfFiles, in: UIDocumentPickerMode.open)
fileBrowser.allowsMultipleSelection = false
fileBrowser.delegate = self
navigationController?.present(fileBrowser, animated: true, completion: nil)
Not sure why, but it shows that empty space at the bottom. Anyone knows what that is?
Found the issue. It was customizing tab bar via appearance. In particular that big chunk of view was some messed up version of shadow image which looks fine in main app, but not so much there. Don't customize your stuff like that people :)