microtones added to xml import

I imported a sibelius qujintet 2 fls, 2cls, pno) as xml and edited it so that I can
use it in dorico w2. satisfied with the results. I added a mezzo voice. all working fine.
I needed a micro-tonal note (as part of the top note of a flute multiphonic). followed the instructions
in the manual (practiced on a new practice file first. I do this often). the microtone displayed fine.
followed the same procedure (sift k then input atonal,l chose 24 notes and the microtone). I get to the
atonal, 24 edo and listing out the possible microtones, but when I choose the microtone needed it resets to 12 edo.

probably part of the import of the xml but not sure how to correct it so that the score can display a microtone.

Are you definitely setting 24-edo first and then inputting the key signature that way round? It really does need to be that order.