When updating to UCS 4.4-6 the update will fail.
Checking the file
/var/log/univention/updater.log you will see messages like this:
Update to = 4.4-6 **** Downloading scripts at Mon Oct 12 09:20:03 2020 Error: Update aborted due to verification error: Verification error: Signature download failed This can and should only be disabled temporarily using the UCR variable 'repository/online/verify'. exitcode of univention-updater: 1
Install this fix and your update should run without issues.