This happens both on a feed as well as within a thread.
Happens both on my direct instance as well as on a random instance out there.
I go to scroll, and there is a nearly one-second pause before the screen jumps to where I have scrolled. If I start very slowly, there is no pause, but I am talking about an unreasonably slow start to the scroll.
Working with an iPhone 15 Pro Max, hardware limitations should not be in play here.