In this case, the wide tooltip was achieved with a very long blueprint name.
Screenshot of the blueprint tooltip in question (on a frame where it's visible): https://imgur.com/of0kkPg - Notice that the tooltip is wide enough to overlap where the cursor is in this case (cursor is over the active 4DEH blueprint). The problem does not occur if the blueprint is on the right-hand column of the book's blueprint array.
I don't have any capability of capturing video offhand, but hopefully the problem is straightforward enough for that not to be needed.
Config details in case they end up being relevant:
- Factorio 0.16.28
- Running windowed, maximised, at 1920 x 1200 on a secondary monitor
- OS: Win 7
- factorio log attached
- Mods: Occurs with no mods loaded