Getting this error consistently over the last week or so.
To my knowledge, no changes that might have triggered this have been made on my server.
cPanel/WHM server on CentOS latest release version. All software up to date.
Added the csf filter to both csf.ALLOW and csf.IGNORE.
Not sure why this is happening. I am going to strip the restrictions and just put the IPs by themselves and see if it replicates tomorrow.