May be not a WAF packet drop.
The work around is to:
1. only complete the mandatory fields
2. then click "Save & Continue"
3. then click "Back" and complete other fileds ("Summary" AND/OR "Add Supporting Documentation" then "Upload Files") as you wish, but one step at a time, repeating steps 2 and 3 as above for each additional completed field,
Good luck 🙂