All trainer floors are that way and have been from the start since the game’s inception.
Yup my bad. thought i beat lector on 11flr but i realized it was all on 12flr (mental lapse) 
Unlucky! Beritus and Lector are both annoying for that reason they only appear on the final two floors… need to get lucky if you’re going to get any gems from the fights.
Except it kind of is lucky because fighting them gets you consolation prizes.
I was unlucky this event for the opposite reason. Often had to re enter a red message door, spending 50 tickets until 1 trainer show up. Happened way to much and took forever to finish.