Is there a way to 'reinitialise' a form...?

Hi All

I have a form that collects user data, as the form is populated manually there are various dynamic tables that can grow / shrink as the user adds / deletes rows. I also have some hidden tables to concatenate text and format it for future processesing. This all works fine as the user builds the form. As per the image below the '+' button on  'Supplier Name' adds a row to the top table and  HIDDENSupplierDESC also adds a matching row for each supplier and concatenates some text. So far so good

My issue is that sometimes users will use an existing form as a basis for their form, update it (adding, amending and deleting fields as appropriate). When this happens I am seeing some strange behaviour Eg image below where only the top row is displayed in the HIDDENSupplierDESC field.

I suspect this is because the table is not being 'built' as the user adds rows by clicking a '+' button. Is there anyway to force the form to 'reinitialise' in some way and as such to populate / concatenate correctly?

Has anyone any advice please?

Thanks

Ellis