I think it is safe to assume that there have been crossword puzzles in Latin, and I think I have seen some in textbooks as well. But what was the earliest Latin crossword puzzle? I do not mean word squares like the Sator square used for mystical or other similar purposes, but actual puzzles that are supposed to be filled in with suitably matching words. I don't know how early such puzzles might be — or how to exactly define a crossword puzzle if there are edge cases — so any puzzles are welcome as answers.
I don't know for how long there have been crosswords in Latin, though I guess that they may date back to the 1920s or 30s, when crosswords were first popularised in newspapers. My teacher in the 1940s used to make them up for us.
They are easily available, though the quality is variable. Just google "Latin crosswords": for instance, https://www.latincrosswords.com/ makes a fairly large claim to being first in the market, but I don't know on what grounds. In the UK, "The Times" newspaper has published a Latin crossword each Saturday for the past couple of years, and the ubiquitous Amazon offers several book titles.