ModSec no longer triggering CSF blocks

I've just noticed that ModSec trigger events are no longer resulting in CSF temp or perm IP blocks. Not 100% sure when this started happening. But LFD stats don't show any LF_MODSEC block triggers within the last 30 days. This is happening across two servers. Neither of which have had any reset configuration changes. I've verified CSF/LFD are running, and appear to be watching the correct log files. Anyone else aware of this issue, have there been any updates to ModSec recently which have resulted in this happening? Any advice where to look?