12/8 meter ties change to improper rhythms

In my score I am in 12/8. I enter the correct rhythms (for example, measure 281). When I apply ties, it changes the rhythms to improper rhythms within the ties. I think I have properly set up the Notation Options/Note Grouping.

See measure 281. I have entered notes with the correct rhythms in the Picc part. Please compare that to the Ob and Cl parts below to see how it changes to improper rhythms within the tie when the tie is applied.

I entered a meter at that bar: [3+3+3+3]/8 Then I hid the meter. Still improper rhythms.

Can it be done properly?
Link to large score in Drop Box:
https://www.dropbox.com/s/j87arfy1miru7sh/Dorico%20J14B%202017-10-09%20meas%20281%20tied%20rhythm%20problem.dorico?dl=0&m=

Please let me know as soon as I can delete the link from the drop box, thanks for all your help!

You need to change (to) this setting (see attached screenshot) in Notation Options > Note Grouping - you currently have the option on the right shown, and you need the option on the left.
You can then also delete your hidden time signature, as it’ll have no bearing on what Dorico does here.

Works, thank you so much!