This might not be for real but...
So I have a few automation scripts I want to appear on the menu / default dock.
I added a new one, a couple of days ago. (A newly installed sticky notes program that I'm fairly impressed with but is definitely in alpha rather than anything else. Irrelevant.)
So a tiny script to launch it, with a + after the name to put it in the right menu. Then a bit of farting around to position it where I want it, seems to be alphabetical.
And the entry I use most is Power Off, just an invocation of the shut down command. It's worked for ages, no issue with it at all.
Except it stopped working.
It's going again now, but I edited it -- deleted the shut down step then put it back.
But I haven't tested in detail and I might be misinterpreting what happened.
Yes, the Dock is alphabetical by design.
I'd need to the see the action used for the Power Off problem that you're having.
Paul.