syn flood

[akanarya]

Hi,
I am experimenting suricata with syn flood.
I observered that it could discard the certain floods but interestingly there is no alert on IDS alert screen.
I am sure that IDS blocked, because when i am disabling the IDS, packets are arriving to the client.
No other parameters were changed.

My opnsense is at the latest version and I am only using ET Pro telemetry rules not others.
Only attack to port 22 is giving "SSH scan" alert.
What is the reason for no alert?
Thanks