The 2. Ringer-Bundesliga (Q210405) was a league below the Ringer-Bundesliga (Q480019). It was suspended in 2017 (c.f. Auflösungsdatum at Q210405). Hence it should not be attached as the league level below of the still existing 1. Bundesliga.
I think the Bot should check the dissolved, abolished or demolished date statement (P576) before adding a league to another one. If the property is set, the link should not be set (at least not in the particular case).