When you say "they are not being shown in the data tab", I hope you mean you are unable to see those properties when you open a proposition from the data tab? Please confirm.
Can you confirm if the decision data is using an auto-generated form or a custom form? If the decision data is using a custom form, the attributes added on the form tab do not automatically show-up on the proposition form; they will need to be added to the customized section.
If not, is there any error in the logs when this happens? Can you share some screenshots for the issue?