As far as I know, Check Point Identity Collector is reading the Active Directory security logs just like the old AD Query did, but with a different (and more robust and scalable) approach.
What I want to say: Have you checked the Active Directory security logs for log-in events from these unix servers? Do they look different, than the ones from Microsoft servers? If yes, do they have the needed and correct information in them?
If the needed and correct information is there, but just the format is different, then Check Point could improve their Identity Collector code to support this scenario.
If the security logs do not contain the correct information, than Check Point cannot do anything and you have to reconfigure (or even patch) SSSD to provide the correct information during authentication process so that the domain controllers have a chance to write usefull security logs.
Sorry, I do not have access to such a setup at the moment to provide you with own findings, I just want to help you to get one step further in troubleshooting, when nobody from the community has answered after a week 🙂
