Dortmund will choose one competition from the Bundesliga and UCL each season. The players have not been able to maximize their strengths in 2 competitions simultaneously. Last season they focused on the UCL and missed the opportunity in the Bundesliga because Leverkusen and Bayern Munich competed for the championship title. Moreover, now they are in 7th position in the standings, but Dortmund played better in the Champions League. The point is Dortmund is not chasing the Bundesliga trophy, the important thing is to secure a ticket to the UCL next season is considered enough.
If currently, Dortmund can focus more on the Champions League, maybe they will be quite successful now. but they also have to secure their position in the Bundesliga. last season Dortmund was left behind by a fairly large point difference from Leverkusen and Munich. and this season, if they no longer focus on the Bundesliga, they must focus on the Champions League. maybe that can be accepted by fans as to why their performance in the Bundesliga is not good enough. now they are 10 points behind Munich, but they still have a big chance to secure 1 position in the Champions League.
The Champions League is indeed quite tiring, plus the tight match schedule. The reason is, they not only have to face the UCL, but also the Bundesliga and the DFB Cup. Dortmund is too focused on the Champions League compared to the Bundesliga and DFB. But fortunately what they sacrificed was not in vain, they performed quite well in the UCL with 3 wins and 1 loss from a total of 4 matches so far, so Dortmund is in a fairly safe position for now.
And Dortmund's average defeat when playing in the Bundesliga, the defeat they experienced after playing in the UCL the previous day. And for more details you can see the following picture. :
We look at it from the first match of the UCL league to the fourth match. In the first match against Club Brugge Dortmund, they won with a fairly large score of 4-2, but after that they failed when facing VFB and lost with a score of 5-1. The 2nd match when facing iceltic in ucl, dormund won again with an extraordinary score of 7-1, but then they lost when facing union berlin in the bundesliga with a narrow score of 2-1. The 3rd match in UCL they faced real madrid and maybe this was a bad week for dortmund, because besides they had to lose 5-2 to real madird, they also experienced a series of fatigue in the bundesliga by Augsburg with a score of 2-1 and the VFB cup second round dortmund also lost narrowly to wolpsburg with a score of 1-0. Finally in the 4th match of UCL, dortmund won again 1-0 over Sturm, but lost again in the bundesliga Mains 05 with a score of 3-1. And looking at dortmund's matches from the three championships they participated in, we can conclude that dortmund is too focused on the champions league. UCL is too tiring for dortmund so they perform less well in other matches.