Without seeing the file, it may be difficult to diagnosis.
However, the general scheme should be:
Wrap the dynamic table in a subform. Set the subform to flowed.
Then, you want to set the parent object, typically the page, to flowed.
That said, changing any object from positioned to flowed may produce unintended formatting consequences. As a rule, I generally wrap all other elements that appear before and after the dynamic table on the same page in subforms and set the object subform property to positioned. Save your form after every action. Then, if formatting goes awry after moving from positioned to flowed, you can simply close and re-open the file.
Good luck.