Errata exclude filter on RHEL6 repo results in wrong amount of rpms


Hope somebody will be able to help me with my problem.
I need to migrate RHEL6 repos from Satellite 6.1.6 to Katello 3.0.
I am able to do that and see proper amount of all rpms and their errata for
main 6server repository imported to Katello.
The problem is … when in Katello I would like to apply exclude errata
filter to my content view of imported 6server repo (to exclude errata
released after Nov 20th 2013 date), I receive ~15K rpms… but applying
exactly the same filter on exactly the same repository in Satellite 6.1
gives me expected ~11K of rpms.

Because like I mentioned my filter is applied in Satellite and Katello on
exactly the same amount of rpms… I got the feeling my errata could be
corrupted somehow, possibly during one of my experiments during import.
When I go to Content->Errata I see majority of errata displayed properly,
but some errata like recent RHSA-2016:1664 for kernel…… does not display
in errata details any of kernel packages but only single python-perf
package…… which is already suspicious… especially if “yum update” for host
assigned to imported 6server repo sees kernel-2.6.32-642.4.2.el6.x86_64
from mentioned errata.

Do you know what can be the reason of a problem or Is there any way to
refresh/recalculate errata for imported repository? I tried repository
deletion and importing again but no joy.

Thanks in advance.