I am also seeing this. Missing Shared actions when the design is updated. When you look into the View design the actions either revert back to the old action or sometimes they point to a totally different shared action.
I had missing actions also. The weird thing is that the action items show in the production application on the client side, but they don’t show in designer (local nor server). So they are there but just not showing in designer somehow.
As a test, I pasted in a shared action from a previous copy of the database just to see if it would show in designer…and it did. So I deleted the action that I just pasted and was going to copy all from the other database and paste all into the db with the missing actions. When I went back to paste them in, they were all “magically” there already.
I think pasting in the action, then deleting it, exiting the db and then going back in may have reset/restored the missing action items. It doesn’t make sense to me. (weird)