They were over reliant on Lewandowski, just a whole cluster of injuries over an 18 month period(I think most are back now) but everyone just dropped out of form, during the injury hit period which was basically all of last year they definitely got bailed out a lot by Lewandowski. Now they just don't seem to be able to get the goals. They scored I think two offside goals, just nothing clicking for them. Statistically there are like 3 teams in the league that have taken 100 more shots than they've conceded against them, IE it's a pretty big sign of being the better attacking team. Likewise statistically a lot of those shots are from within the area, they are good chances. Just 18 months of some major injury problems and everyone being out of form and then when everyone is out of form it's harder for any single player to get back to form.
IE take someone who missed a year with a serious injury and put them in a side playing great and he'll get back to form quicker, the pressure is off, others will score in games, no worries in the league and the player desperate to score will not be as pressured. A few bad weeks, starting off low down the league and being under deep pressure, it's really a position these players haven't been in. If Lewandowski was there he'd probably have got a decent number of goals, finished up plenty of the games, they'd be at worst mid table and the team would be playing better more relaxed football.
it's not good, they aren't playing well and Klopp hasn't managed to get a handle on it. If they can get a couple of wins, even if entirely flukey, you'd probably see them jump into decent form and shoot up the table. Genuinely worried they might end up relegated at this rate though.