Alfa production is only in Italy, so the figures below provide a complete picture. 2017 was 147,000 (+71%) but in 2018 it was 110,000 (-25%). That's quite a turn around but shouldn't be totally unexpected. Besides, back a few years in 2015, production was barely 60,000 so gains have been made.
When a smaller brand enters (or reenters) a new segment, pent up demand pushes up sales and then they go down. The Giulia and Stelvio did just that in 2017 but the big dip followed. That will continue in 2019 as the end of the fall occurs and as sales soften generally. Former FCA Sergio Marchionne had high hopes for Alfa but they were optimistic.