Scrolling artifacts on mobile at low FPS

Weird artifacts appear when scrolling through textures in a scroll box. This is more noticeable and happens more frequently at lower frame rates. View AnswerHub thread for examples of artifacting.

1. Download and open the attached project
2. Open "Test" level
3. Launch on to a mobile device that supports metal (I used an iPad Air)
4. Alternate between scrolling with your finger and clicking the green check mark
5. Notice that stretching and artifacting occurs

Expected: The textures would scroll up and down
Result: The textures stretch and create artifacts

iOS - UMG widgets render errors on Metal with Scroll Box