When I switch to Reader view in FF for iOS (text-only view), I can sometimes scroll smoothly to the bottom of an article, and sometimes Reader view suddenly starts yanking me down to the bottom of the web page when I attempt to scroll down. What do I mean by 'yanking'? I scroll down a screen's worth of text, read the next screen, and scroll again, read again, and at seemingly random moments, the view scrolls by at rapid speed to the bottom of the page. I can then try to scroll up--and it will let me scroll rapidly, pulling up so quick that the scrolling continues a moment to catch up after I remove my finger from the screen--but as soon as I try to fine-tune by touching the screen and holding it as I move it up and down a little at a time, YANK! and I'm at the bottom of the screen again. Sometimes I can leave reader view, reload the web page without leaving the page, reset to reader view, and be successful at scrolling the entire article. Other times I have to close the web page and open a new window to start over.

This happens on more than one website, and has been a problem through multiple iOS iterations (at least since iOS 14) and FF updates (I keep my FF on auto-update). Currently on iOS 17.0.3 iPhone 12 mini with FF 118.2 (34971).