Hello Udo,
Thanks for your reply.
I also assumed that the rule was no longer working properly due to the development. So I copied the check and the rule to a fresh new site and I got the same error.
Unfortunately there is no clear identification in this OID or any other OID in the head section. Either it says something about Linux and the distribution that could match on many other (Non-Zertificon) devices or just the hostname that only matches on that one device.
The rule should match for all Zertificon devices. But the enforced rule is entirely fine for my purposes.