Ideally when we create a table extending another table, system should inherit the fields from base table and populate it in the child table.
However, at times, the child table doesn't get all the fields from parent table as shown in below screenshot.
Any supported release.
Child table was created and then deleted for some reason. When the table was deleted, not all the relevant records (sys_storage_alias, sys_storage_table_alias) were not deleted at the back-end.
Hence, recreating the table with the same name and same extension, table is not created with inherited fields as expected.
Please open a HI incident with "Tables and Dictionary" category, so that support can help you with clearing the leftover records of the deleted table via change request.