Why is my iPhone glitching when scrolling?
The most common factors of the probable cause of the automatic screen scrolling include a tight iPhone case, damaged screen protector, faulty display, internal system problems, broken display settings, or device assembly resulting from a damaged pin.
How can I make my iPhone scroll easier?
In other words, you scroll faster on your iPhone or iPad by holding down on the scroller for a moment and then dragging it up or down. For those wondering, it's a system-wide gesture. You must first trigger the scroll bar by scrolling some, then touch and hold the scroll bar itself a bit.