Easy beacon duplication glitch

There is a very easy beacon duplication glitch available on Bedrock Edition for mobile devices. It allows you to get a full stack of any stackable item very easily.

How to Reproduce:

1. Using a touchscreen device (it might work on PCs, but I haven't tested it), open a world.
2. In the "Settings" menu, under "Video", set the "UI" to "Pocket" mode.
3. Exit the settings menu and go back into the world.
4. Place a beacon on the ground. It does NOT need to be activated, although it will work regardless of it.
5. Get a stackable item and put it into your hotbar. You may use any item.
6. Tap on the beacon. You should now be in the beacon UI.
7. Rapidly tap on the item in your hotbar.
8. The stack size should multiply by 2 every time you tap twice (in quick succession).

Extra Notes:

1. This will never let the stack size exceed the maximum for that item (in my testing). For example, unstackable items will never duplicate, items that stack to 16 (such as ender pearls) will duplicate up to 16, and other stackable items (seeds, logs, end stone, diamonds, etc.)
2. From my testing, this will not work in the "Classic" UI.
3. I learned about this bug/duplication glitch in a YouTube video: https://youtu.be/3p2AHb6XriY?t=40. This has a better demonstration of this than I could ever provide. Also, the video URL is provided with a timestamp going straight to the part where this glitch is discussed.