The status for all blades including IPS is pulled from the cpd daemon running on the gateway. Anything interesting in $CPDIR/log/cpd.elg on the gateway around the time of the last IPS status failure?
It also possible that fwd may be involved with reporting the status of the IPS blade, which did not have its own individual status reporting until R80.20, so may want to look in $FWDIR/log/fwd.elg as well around the time of the issue.
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