I've had the same yesterday on my new core.
1. Check your DNS settings:
- System Properties:
- Tab Computer Name
- Press Change button
- Press More button
- Change "Primary DNS Suffix of this computer"
2. Check the registry key on the core for HKLM\Software\Landesk\ManagementSuite\Stamping\Data\CoreServer, change it to the FQDN or (IP-Adress)
is this entry "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurePipeServers\winreg" different between 8.7 and 8.8?
On my 8.7 cores the group "LANDesk Management Suite" has read rights only...
Mine is Read. Should work with both, and I always go with the least amount of rights. Doc says full. I would personally start at read and test. Also make sure the remote registry service is started.