Filter rule association: add unassociated filter rule

[sirio81]

Hi, I created a port forward as test:
2222 -> 192.168.178.99:22
I chose "add unassociated filter rule".
I expected to find a rule in Firewall / Rules / Wan that I was able to edit but I see no related rule.
Is it a bug or am I misunderstanding the meaning?

Nontheless, If I click on the pencile to edite the "Nat / Port forward rule", the Filter rule association is "None".

Thank you.

OPNsense 18.1.6-amd64