Actually, in the UCL this season, I initially hoped to see surprises from several clubs that made surprises in the domestic league last season. Like Leverkusen, who made an unbeaten record in the Bundesliga, Girona, who was even a very strong team last season in La Liga, then there is Bologna, who was also surprising in Serie A because they managed to finish in 5th place without anyone expecting it. But it looks like Bologna and Girona are having a tough start to the UCL. Meanwhile, Leverkusen looks like they are starting quite well in the UCL. Because until now Leverkusen has not lost in the 2 matches that have been played.
You should also check their performance in their own domestic league in this season, both Bologna and Girona performance are terrible, while Leverkusen is still fine even though not as strong as in the last season. But, Leverkusen met easier opponents, like Milan and Feyenoord, which is nothing surprising they can won those match.
After all we still have many upcoming match, Girona is quite lucky their opponent not that strong.