When querying data from a data mart table or view, the listed results are not up to date or missing.
The data mart tables and views are updated periodically in the background, but not in real time. Due to this, it can take a few seconds up to a few minutes for the data to be loaded into the data mart tables. If your system is running a heavy load, this influences the performance of the background process which is loading the data. The reason is that other processes are prioritized higher and may temporarily block the DataMartUpdater background job. Run your query again later to retrieve updated data.
If you are logged in as a system administrator, you can check the current state of the data loading process by navigating to http://<server>:<port>/sctm/check/db and checking the DM_TestStatus Table.