Hi there Wil V,
I have exactly the same problem as you described. Have you found a solution yet?
A textbox is prefilled with blank value that i cant restore to its original state. I try pressing the orange arrow and saving. No result. I try pressing the garbage can that says "delete prefill or control" and then save. No result. The users are facing the same issue still.
The only solution I have found is to create a completely new flavor.