The standby server in version 8.20 does not update values from the server if the runtime files (Service Engine files) were created for version 7.60 and of the servers are running in version 8.20.
(Recognition and updating of values only works consistently, when the Runtime files created for version 7.60 are loaded by version 7.60 Server runtimes)
To use this fix:
Upgrade Server, Standbys Server and clients running in version 8.20 (and higher) to a build that includes the fix.
Connect the 8.20 (and higher) Clients to the server with created runtime files for versions lower than 8.20.
Restart the Runtime (Service Engine) on the client.
After the 2nd start, the values are updated.
Note: Clients with older versions can be connected, but value updates fail (e.g. numeric elements will remain empty).