A download using the HTML5 download anchor attribute can no longer be initiated, if the event handler function has some sort of delay. Try clicking the buttons in this demo: https://codepen.io/marto55555/pen/xxZbJqX?editors=1010.
This used to work in Samsung Internet and still works in Chrome, Opera, Edge, Firefox, iOS 13 Safari.
Last working version: Samsung Internet 184.108.40.206
First non-working version: Samsung Internet 220.127.116.11