Subform handling that worked on the old platform is no longer producing the same results!

I have a form that was created on the previous Creator platform. This form contains a subform and is working fine. I created a new form using the old form as a template. I had to use a different subform in the new form. The new subform is an exact copy of the old subform. The code is identical in both forms. The new form does not produce the same results as the old form.

In the old form the code listed below returns the string with the contents of the subform field Activity. This is exactly what I want.
In the new form the same code returns the record ID.

It appears that the handling of the subform changed between the two versions of the platform. Is there any way to return the string with the contents of the subform field Activity in the current Creator platform?

Working code in the old form:

for each m in Dummy_Activities_Weekday [Schedule_ID = input.ID.toLong()]
                {
                    insert into Add_Activities
                    [
                        User = input.User
                        Schedule_ID = rec.ID.toLong()
                        Activity_Date = dte
                        Activity = m.Activity
                        Type = m.Type
                        Day = day
                        Planned_Hours = m.Planned_Hours
                        Added_User = zoho.loginuser
                    ]
                }

Non working code in the new form:

for each m in Dummy_Activities_Weekend [Schedule_ID = input.ID.toLong()]
                {
                    insert into Add_Activities
                    [
                        User = input.User
                        Schedule_ID = rec.ID.toLong()
                        Activity_Date = dte
                        Activity = m.Activity
                        Type = m.Type
                        Day = day
                        Planned_Hours = m.Planned_Hours
                        Added_User = zoho.loginuser
                    ]
                }

Thank you in advance,

Henry
henryc@applez2applez.com