Client is failing to download this particular kernel package from Katello UEK 5 repository. I have no issue with downloading other packages from other repositories. I have tried different options like resyncing the repository and creating new content views. Also have cleared the cache from proxy .
first off, this is usually a problem with the upstream repository. The Package does not match intended download message indicates a checksum problem with the repository you’re trying to sync. The downloaded package does not match the checksum from the metadata for the package, so the download is refused.
Secondly, the Versions of Foreman and Katello you are running are really old, several years by now. You should definitely consider upgrading asap, since a lot of bugs have been fixed since then and support for ancient versions is somewhat hard to get if you hit a real bug. Probably, no one will have a version anywhere near that to even reproduce your issues.