Yes, this is the problem. Unfortunately, Bayern Munich's main game since the beginning of the season has been that consistent, they are very different from what they experienced last season. In fact, they are much more solid and strong this season, never having been defeated in the Bundesliga so far. Therefore, if they are to chase the Bundesliga title again, it seems impossible for them. At most, Leverkusen still has a chance for the FB Pokal trophy.
While Leverkusen's condition at the beginning of the season was quite weak, especially in their defense line which was quite down, with the number of goals conceded at that time. Then, because of several injury issues that started the season, while the club did not have many reserve players who were that strong.
You are right Bayern Munich has been very consistent this season and has improved a lot from last season. Fact is that they have not lost game in Bundesliga yet shows how strong and solid they are. Because they are doing so well it us unlikely that any team including Leverkusen can catch up to them in race for Bundesliga title. Leverkusen best chance to win something might be FB Pokal trophy. However it is worth noting that Leverkusen has shown that they can bounce back and improve even though they started season poorly and had problems with their defense and injuries. Their ability to adjust and overcome these challenges will be very important if they want to win FB Pokal trophy.