Hi !
Ok Imagine you want to edit this voice :
And you want to change the first beat from a dotted eighth (3/16 1/16) to a triplet (1/6 1/12).
First you delete the notes of the first beat :
next step will be :
and then :
now, if you try yo group the first two rests of the triplet, shit happens :
the same thing is not happening if, instead of editing a voice, you edit a voice INSIDE a poly :
(here we get the properly grouped rests).
This bug is there since the beginning of times, sorry to report it just now …