ip in the csf list but not blocked

[jehanzaibkiani]

Hi,
I have blocked an ip xx.xx.65.81 but i can still see ddos attack from that ip.
csf -l shows that DROP rules have been added as shown below:

200 2 1450 DROP all -- !lo * xx.xx.65.81 0.0.0.0/0
200 4 1840 LOGDROPOUT all -- * !lo 0.0.0.0/0 xx.xx.65.81

The IP is present in the /etc/csf/csf.deny file. lfd and csf both services are running.
csf version is v14.10

Is there anything else i can look at ?

Thank you