same problem here, only recently though. I'm rated about 1100 in blitz and rapid, but I lose to bots rated 600 or lower with a 90%+ accuracy. really annoying
Bot Differences on Mobile App and Website....

Martin (250) can easily beat me with 95% accuracy, I really wish chesscom would fix this. Normally I can premove half my game against Martin and still easily win

It's not just a "human" bot issue, I just played the engine on level 1 (250) and got completely out played. Engine had 93.8% accuracy! With a rating of 250!! http://imgur.com/a/RhLa124 This is a horrible bug that should be fixed quickly. Chess.com may have new players coming to this app to start out and will immediately be put off by the insanely high skill of the lowest rated bots.
When I play the 400 elo Filip bot on the website (desktop) it struggles to get over 10% CAPS with even the most obvious free moves, but on the mobile app (android) it plays theory and scores a minimum of 70% CAPS. On the mobile app the main weakness it seems to have is not castling ever, where as on the website it hangs pieces religiously. I don't understand how these could be so different... do you all have two different APIs for the mobile app and the website?