At the beginning of the season they performed a little better in Serie-A and they got a much more convincing game pattern. But in the last six games Fiorentina started to struggle to develop their game and even struggled to get wins. The quality of the players they have is not as good as some of the top teams in Serie-A and maybe that is what needs to be improved so that they can compete with the top teams in the next season. The focus now is to finish the League in the top five so that their motivation in the next season will be much greater and that is not easy because they need to show consistency so as not to lose many more points in the next match.
Fiorentina decline started in their last 6 or 7 games just as you have said, earlier on in the season, they were doing well but declined all of a sudden, maybe their squad depth isn't enough to stay at the very top in which they had planned to, maybe fatigue has set in for the players and they are tired that's why they have this sudden decline in form which has been affecting their recent run of form.
We are currently having just Napoli and Inter Milan in the best shape with all other top teams are facing troubling time Atlanta is now also having 3 draws streaks which bring them from 1st to third and Juventus is now heading for another record as their draws are 13 from their 20 games while no lost which is positive.
AC Milan is surely having good change now they are going to visit Turin for next round game which is surely big challenge for them after having 3 wins and 1 draw with new coach Conceicao AC Milan is having good record against Juventus which will give them good advantage.
Few teams always suffer badly after having good start same happening with Fiorentina as they are winless in 6 games and their problems are increasing if they are not able to have good result against Torin which is also playing with tight defense and having 3 matches draws streak.