I use Split View often to compare drafts, but I’ve noticed a bit of weirdness while using the current beta. If I have a completed document in one pane, and I start typing in one of the panes, especially if it’s wider, paragraphs in the other pane disappear, leaving a space as large as the paragraph was. They seem to line roughly line up: typing near the start of the first paragraph will make the first paragraph disappear, typing near the end or at the start of a second paragraph will make the same disappear, and so on. Not only that, but the editor seems to think the text is no longer there; if I move the cursor to just before the vanished paragraph and tap down, it disappears. Another tap down will move it to the start of the next paragraph, as if all the lines in the paragraph are gone.
It reappears if I adjust the size slider in between the split, or type something when the cursor is in the purgatory in between paragraphs. But considering the pertinent text turns invisible as soon as I type related text in another document, it’s more than a slightly irritating error.