Oracle full version is not displayed in the databases dashboard for 18c and higher versions.
Foglight shows only the major release version for Oracle 18c and higher versions instead of the full version.
Foglight displays the full version for the instances running on 11g and 12c. In versions like 11g and 12c VERSION column from v$instance table is queried by Foglight to display the full version of the instance. Starting 18c VERSION_FULL columns stores the full version instead of the VERSION column. Since Foglight is reading the VERSION column the major release version is displayed instead of full version.
Waiting for fix in a future release of Foglight for Oracle cartridge.