Answer
Make sure the read and the write are both done as IFS Projection tasks against the same projection and entity set as the page itself uses (e.g. both against CustomerOrderHandling / CustomerOrderSet) rather than mixing task types — a mismatch there is a common reason the workflow's own observation looks correct while the client never actually reflects the change. Also check whether your read step returns a collection rather than a single record; if it does, you need explicit sequence/looping handling around it, since an unhandled multi-record return can silently break the chain of tasks that follows it.