Sincere apologies. A further issue has been identified in which initial upgrades to 2.2.14 may have set the default 'http' option for the unsubscribe option incorrectly.
The latest patch will workaround this issue if you are affected.
Alternatively, going to Options > Email options in your admin control panel and setting the "Unsubscribe email handling" option as desired will fix the issue without needing to upgrade.
This is being rolled out to existing Cloud customers automatically if affected.