You’re not missing anything.
It sounds like “the Elektron pattern changing bug” that seems to happen across AR, A4, OT, DT and DN. Roughly speaking it’s triggered by having any “advanced” scale settings (but it’s like 95% like that. I’ve seen it happen occasionally with AR+OT when neither uses track-specific scales).
Elektron are looking into it. They’ve known for a while. Recent responses have suggested they didn’t feel they had a consistent testing strategy before, but that they do now.
But also… I’m inclined to be generous to Elektron. If you have a pattern with a mixture of fractional and multiple step scales, and a Master Length and Change Length set differently, which one actually is the Change length? If CHNG is set to 16 steps, is that 1/4x, 1x, 2x? It’s probably different for different tracks. Some 2x tracks will be “well, I don’t mind if this gets cut off” whilst others will be “this is the melody/bassline, it must complete before the pattern changes or the song will suck”.