Can you try to deselect the writeNow checkbox in the Obj-Save method and add the Commit method after performing the changes to the data page. Also can you share the configuration details screenshots along with the tracer log if it still doesn't resolve your issue.
I had tried to remove the Obj-Save with a property update and commit, but the data is not being saved. So i had implemented your requirement with a sample use case and the data is being updated as expected.
Kindly go through my attachment for further information.
Thanks for the suggestions. Even I was able to achieve the functionality using a temp page but I was curious to know if we can achieve the same without using temp or additional page as below article says editable data pages are database persitent. So not sure what that actually means.