The analysis ELO guess is puzzling me. I recently played the 1800 level bot. At the end of a humbling defeat, I played like an 1850 (nope, I'm 1100); but the bot apparently played like a 2500?!? So is the ELO guess wildly wrong, or is the bot allowed to play well outside its assigned ELO?
I can't say for sure, but sometimes chess bots can be playing normally at the beginning of the game but suddenly become stockfish mid game and destroy you. Don't quote me on that though I haven't fully confirmed it.