Where are the mon researchers?
Most of my mons respawned after the 48 hours mark, but a little before the 72 hours mark. I started doing my rounds on tuesday at 08:30 am, and they reappeared today at 07:30. That's after waking up, so I don't know the precise timing.
Also, last time I had this same mon behind the waterfall and now it's the shiny variation. Not sure if it's just a coincidence or if it's just a fixed chance for it to respawn as shiny. I also had a random boxie on the fortress last week, but in the next respawn it wasn't there.