Is your Kindle e-ink?
The general issue with e-ink-based readers and scrolling is that e-ink is designed to be mostly static, with sporadic (preferably partial-page) refreshes; but scrolling needs to have a very high refresh rate that updates the whole page simultaneously if it’s going to be usable.
Instead of trying to detect and block it, just disincentivize it.
Most AI spam on social media tries to exploit various systems intended to predict “good” content on the basis of a user’s past content by tracking reputation/karma/etc. Bots build up karma by posting a massive amount of innocuous (but usually insipid) content, then leverage that karma to increase the visibility of malicious content. Both halves of this process result in worse content than if the karma system didn’t exist in the first place.