Strange beaming behaviour

I am trying to recreate this beaming :

and all I could get is
Slice 1

When I select partial beaming for 16th , the program is canceling this option and it seems there is nothing I can do to fix this.
Any ideas?
THanks

What happens, if you Select the first and the last note and then Beam Together?

Check engraving options. There are oodles of settings for beaming and I believe there is one that covers this scenario. Not at my computer at the moment to confirm though.

Notation Options:

image

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You may have to fiddle with the Beaming => Split Secondary Beam property for the middle notes.