I have a Secure Note with "a lot" of text, approx. 150+ "lines" of text (which is 700+ words), with markdown formatting, and when I go to the item (such as by tapping on it from Favorites), it usually shows a bunch of extra whitespace below the note (but within the note area). The whitespace is approx. 1.5-2x as much as the note itself. In other words, if it takes me 5 full-page scrolls to reach the end of the note, it takes another 9 scrolls to reach the bottom. Hope this helps.
I took a screenshot, but I think I pretty much described it. My 1Pass version: 1Password for iOS 8.10.3 81003001, on BETA channel
1Password Version: 8.10.3 81003001, on BETA channel
Extension Version: 2.7.x
OS Version: iOS 16.x.x