The file selection popup on iOS does not always open next to the file select popup. This is possible to replicate on the main page for the angular upload component https://www.telerik.com/kendo-angular-ui/components/uploads/upload/ and the stackblitz as well without any modification
https://stackblitz.com/run/?file=src%2Fapp%2Fapp.component.ts
Screenshot shows that the photo library/choose files popup opens in a seemingly random spot after the user taps it.