Alex B's answer to a recent question mentions that we have no extant texts from Ovid before the high middle ages. As books are perishable on the timescale of centuries, having extant material today often relies on a long unbroken tradition of copying ancient texts. Some of these copy chains must have been broken; I have to imagine that this has happened to several classical Latin books for reasons of religion, preference, fashion, or chance.
I also imagine that we do have some records of what has been copied even when the copies themselves have been lost. Perhaps the records are not systematic, but there must be some mentions out there. (Please let me know if there is anything wrong with these premises.)
These two ideas lead to a question: When have we last lost an ancient Latin text? More precisely, what are (some of) the most recent examples of texts that we know to have been copied but have since been lost? What is the most recent date of such a loss? Did, for example, all texts that made it to the year 1800 make it to our day?
I prefer classical Latin, but all eras of antiquity are welcome. I would like to exclude texts that have been salvaged by other means (like recent papyrus findings) and focus on texts that have actually been lost in the past half a millennium or so. (Salvaged texts would also be interesting, but they are best taken to separate questions. We could also have a question on the different ways texts have survived: copy tradition, papyri, palimpsests…)