Problem
It is not possible to fill in both Discount amount and Discount percentage at the same time.
Possible cause
A discount code can only give either a fixed amount or a percentage — not both. The system automatically clears one field when you fill in the other.
Solution
Decide whether you want to use a fixed amount or a percentage.
Fill in only the relevant field and leave the other empty.
If the problem persists, contact support and include details about:
What you tried to enter in the fields.
When the issue occurred.