We print flat down UNSUPPORTED dental models up to 8 on the tray with NO issues.
We changed reg tray to LT tray recently.
We had 2 misprints whith a hole in the model in the occlusal. Second one is the lingual side of the centrals - i can attach a pic!
Before that we have NEVER had a misprint and have been printing for a year.
I don’t see a picture yet, but if it’s a tiny vertical hole right through the model, it could be a piece of dust on the main mirror, printer window, or the bottom of the tank that’s blocking the light in that one spot.
Go back to the the regular tank and reprint the model. I had trouble with the LT tanks printing dental models. IMO, I think the z axis is different between the two tanks on my form2 and was causing issues. I tried several things with Formlabs support, but in the end going back to the regular tank fixed my problem.