Also, as debugging, create a new profile where you set everything to alert that is: Critical: Alert High: Alert Medium: Alert Low: Alert Informational: Alert and then create a new security rule (only for this particular srcip or if its dstip in your case) above the current one. In this new security rule attach the new vuln profile from above. Now you should hopefully see what is being identified for this traffic flow. If you are not comfortable with setting all levels to Alert you can set them to Block (since this is just debug) - blocked traffic should be logged if you have set the "log on session end" (I guess "log on session start" wont pickup any threat). However isnt the Threat log on its own not depending on what the security rule itself is set to? I mean I though the security rule was regarding Traffic logging. If a vuln should log or not is set in the vuln profile itself (such as Alert means log only while Block means block and log, while Allow will not log at all (for this you use Alert instead)).
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