I can confirm this does not work, but I don't know why (tried in 22 and 26).
If you change the criteria so it does not include the fill (i.e. just all types), it does work.
But as soon as you want to override a particular fill it does not override the morph.
I would report this to your local Archicad support to see what they say.
If it is a bug, they can pass it on to GS HQ.
One of the forum moderators.
Versions 6.5 to 25
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Dell Precision 3510 - i7 6820HQ @ 2.70GHz, 16GB RAM, AMD FirePro W5130M, Windows 10